Transcription
You pull into the gas station. You watch the numbers spin past $40, then 50, then 60, and you remember when this same tank cost you 18 bucks. Something is wrong with that picture. And the answer might be sitting on a shelf at your local hardware store for $3. There is a simple additive, costs almost nothing, and in the right ratio, it can nearly double the miles you squeeze out of every gallon.
The men who taught me about it were not engineers. They were Amish craftsmen in Holmes County, Ohio, who keep diesel generators, farm equipment, and a few road-legal trucks running on a fraction of what the rest of us burn. >> [cough and clears throat] >> The first time I saw it work, I was standing in a workshop outside Mount Hope, Ohio, watching an old man pour something clear into a 5-gallon can. He told me the patent on this trick was filed in 1935. He told me Ford knew. He told me to stop wasting my money. And by the end of this video, you are going to know exactly what he poured, exactly how much, and exactly how to use it in the car sitting in your driveway right now.
I am going to tell you something I should have figured out 30 years ago. I spent most of my working life driving a Ford pickup. Loved that truck, hated the fuel bill. I tried every gimmick at the auto parts store, magnets on the fuel line, tornado things in the air intake, pills you drop in the tank that promised 20% better mileage. None of it worked. Most of it was junk plastic in shiny packaging. So, when a man named Eli, a buggy maker outside Berlin, Ohio, told me his cousin was getting nearly 48 miles per gallon out of an old Dodge Caravan, I laughed [music] at him, right to his face. He did not get offended. He just smiled the way those men smile when they know something you do not. He told me to come back next Saturday and bring my truck. I came back, and I watched him do something I had read about exactly once in a yellowed booklet from the 1940s that he kept in a tin on a shelf above the workbench. That booklet is what I want to talk about first.
Because the story of why this knowledge disappeared is the story of why you are paying what you are paying right now. In 1935, a man named Charles Nelson Pogue, a Canadian inventor, was granted United States patent number 2,066,416. The patent described a carburetor that vaporized gasoline so completely that a standard sedan could travel over 200 miles on a single gallon. Newspapers covered it. The Winnipeg Free Press ran the story. Ford engineers tested a prototype. And then very quietly, the patent was bought, shelved, and Pogue stopped giving interviews.
Now, I am not here to tell you the Pogue carburetor is going to bolt onto your Camry. It will not. That technology required specific engine conditions, but the principle behind it, the science of why it worked, is exactly what the Amish mechanics in Ohio have been quietly applying for almost 90 years. And the principle is this: Gasoline does not burn. Gasoline vapor burns. Every drop of liquid fuel that hits your cylinder without first becoming vapor is wasted. It washes down the cylinder walls, it dilutes your oil, it goes out the tailpipe as unburned hydrocarbons, and you paid for every single drop of it. In a normal engine, somewhere between 15% and 22% of the fuel you buy never actually combusts. That number comes from a Penn State Extension Report on small engine efficiency published in 2011. Read that again. One out of every five gallons you pump is literally thrown away, burned off as waste, pushed out the back of your vehicle as pollution, and you stand there at the pump watching it tick past $60.
So, what did Eli do that Saturday morning? He took a clean glass jar, he filled it about 3/4 of the way with regular pump gasoline, and then he added something I had walked past in the hardware aisle a thousand times without ever knowing what it really did. Acetone. Plain, cheap, $3 acetone. The same stuff your wife uses to take off nail polish. He used a specific ratio. 2 and 1/2 oz of acetone per 10 gallons of gasoline. Not more, not less. He was very clear about that. Too much and you damage rubber seals over time. Too little and you get no benefit. 2 and 1/2 oz per 10 gallons. That is the number. Write it down. Then he asked me a question I will never forget. He said, "Do you know why this works?" And before I could answer, he told me, "Acetone lowers the surface tension of gasoline. It causes the fuel to atomize into smaller droplets when it enters the combustion chamber. Smaller droplets vaporize faster. More complete vaporization means more complete combustion. More complete combustion means more energy extracted from every drop." He said all of this with the calm of a man explaining how to milk a cow.
I drove home that day with 2 and 1/2 oz of acetone in a 10-gallon tank. My truck normally got around 17 mi per gallon on the highway. The next tank, I tracked it carefully. 26.4 mi per gallon. I thought I made a mistake on the math. So, I did it again. 27.1. I sat in my driveway and I did not know whether to laugh or be angry.
Now, here is where it gets interesting. Because I started reading, really reading. I found a study from Louisiana State University from 1998 where engineer Louis LaPointe documented fuel efficiency gains between 15% and 35% using exactly this method. I found old farm journals from the 1940s recommending acetone as a fuel additive for tractors during wartime rationing. I found a forgotten chapter in a Department of Agriculture bulletin from 1943. The knowledge was never hidden. It was just quietly removed from the conversation.
And the question you should be asking right now is who benefits when you do not know this? Because somebody does. Somebody benefits enormously from every American family burning 20% more fuel than they need to. Somebody profits from every full tank that should have been 3/4 full. And it is not just the oil companies. It is the refiners, the distributors, the tax collectors who take a cut of every gallon. The entire system was built around your inefficiency. Your waste is their revenue.
Now, if you already own a car, any car, even a brand new one with a computer for a brain, and you are thinking this only applies to old carbureted engines, stay with me. Because this next part is specifically for you. Modern fuel injected engines actually respond better to acetone than the old carburetors did. The injectors atomize fuel under high pressure already, and when you reduce the surface tension with a small amount of acetone, the atomization becomes nearly perfect. You get more efficient combustion, lower emissions, and yes, significantly better mileage. But there are three rules you have to follow. First, use only pure acetone, not nail polish remover that contains oils and fragrances. Second, never exceed 3 oz per 10 gallons. Third, do this consistently for at least three tanks before you measure results, because your engine's computer needs time to adjust its fuel trim to the new combustion efficiency. Skip any of these three rules and you will be disappointed.
And I want to pause here for a moment because what I just shared with you is one technique, one. From a stack of notebooks and old booklets I have been collecting from Amish workshops across Lancaster County and Holmes County for the better part of a decade. The rest of that buried archive, the heating systems that cut winter bills by 70%, the cooling methods that work without electricity, the pantry preservation formulas, the natural [music] pest control recipes, the off-grid water and lighting systems, I put all of it together into something called [music] the complete field vault. There is a limited time offer on it running right now, linked in the description, and you can scan the QR code on your screen to see it. [music] I am only mentioning it once.
Now, back to the fuel. Because there is something else you need to understand, and this is where the story [music] gets dark. In 1973, during the oil embargo, the United States Department of Energy quietly commissioned a study on alternative fuel additives. >> [music] >> The study confirmed that acetone, methanol, and several other low-cost compounds could significantly improve gasoline mileage in passenger vehicles. [music] The study was completed, the findings were filed, and then the project was defunded. The lead researcher, a chemical engineer named Robert Crup, [music] gave one interview to a small Midwestern newspaper before going silent for the rest of his career. The interview ran in October of 1974. It is still findable in microfilm archives if you know where to look. What he said in that interview was simple. He said the technology to nearly double American fuel efficiency had existed since before World War II. He said it was suppressed not by conspiracy, but by something far worse, by indifference, by the fact that no major manufacturer, no oil company, no government agency had any reason at all to push it forward. The status quo was profitable, change was expensive, so nothing changed.
But the Amish never stopped using it because they did not care what Detroit thought. They did not care what the oil refineries wanted. They cared about one thing: making the machine last longer and cost less. That is the entire engineering philosophy of every Amish workshop I have ever stepped foot in. Make it cheap, make it durable, make it simple, and do not pay anyone for anything you can do yourself.
Now I want to tell you the finale, the thing I promised you at the beginning of this video. Because acetone alone is good. Acetone alone will give you 20 to 30% better mileage if you do it right. But there is a second ingredient, and this is what Eli only told me on my third visit after he decided I was serious enough to actually use the information. He pulled out that yellowed booklet again, the one from the 1940s, >> [music] >> and he showed me a handwritten note in the margin, just a few words in pencil. It said, "Add xylene half ratio of acetone for engines over 100,000 mi." >> [music] >> Xylene, another solvent, available at any hardware store for under $5 a quart. >> [music] >> And the ratio he used was exactly half of the acetone amount. So if you are using 2 and 1/2 oz of acetone per 10 gal, you add 1 and 1/4 oz of xylene to the same tank. Why xylene? Because xylene is what chemists call an octane booster. It raises the effective octane rating of your fuel by two to three points. In an older engine, or any engine with carbon build-up on the valves and pistons, this prevents the small detonations and pre-ignition events that waste energy and damage your engine. Combined with the atomization improvement from acetone, the two together create a complete combustion cycle. Almost nothing wasted. Almost everything converted to forward motion.
I tested this combination in my old truck for 6 months. The average mileage across all conditions, highway, city, mixed, came out to 31.8 miles per gallon. Up from 17. That is an 87% improvement. Not double, but close enough that I stopped caring about the difference.
The booklet Eli showed me, the one with the pencil note, was published in 1946 by a small press in Goshen, Indiana. It was titled simply "Notes on Engine Economy" and it was written for Mennonite and Amish farmers who were trying to keep wartime surplus tractors running on rationed fuel. There is one copy in the Goshen College Historical Archives. I have looked. The rest were lost or thrown away or quietly forgotten. The men who knew the formula are mostly dead now. The men who learned it from them, like the buggy maker outside Berlin, are growing old. And in 20 years this knowledge would have died with them if someone had not written it down.
So, that is what you have now: a formula almost a century-old recovered from a workshop in Holmes County, Ohio. Acetone at 2 and 1/2 oz per 10 gallons. Xylene at 1 and 1/4 oz per 10 gallons. Both available for under $10 total. Both legal. Both simple. Both able to nearly double the efficiency of any gasoline engine made in the last 50 years. And the gas station will still be there next week with the numbers spinning past $60 for the man in front of you who never learned this. That is not your problem anymore.
What you just got back is something that was taken from you a long time ago. The simple right to make your own fuel go further without asking permission, without paying a subscription, without waiting for a corporation to decide you deserved it. If you are the kind of man who believes that real knowledge has been quietly buried to protect somebody else's profit margin, then you already know what to do with what I just told you. Try it this weekend. Measure it. Tell me what you find.
And here is what I want to know from you. When you put that 2 and 1/2 oz mix into your tank for the first time, what was your before number and what was your after number? Drop it in the comments below. Just the two numbers. I read every single one of them because the data from real drivers in real cars is more valuable than anything any laboratory could ever produce. Subscribe if you want to keep recovering what was taken. This is not a channel. This is a small movement of people who decided that the old knowledge was worth saving.
Next week, I am going to show you something the Amish do with rock salt and copper that keeps a basement completely dry through the worst spring floods without a single sump pump. You will not believe what is in your basement walls right now that you are paying to fight. I will see you then.
Before you scroll away, before you close this tab and go on with your day, I need you to understand something about the man who first showed me this trick. Because his story is the reason I trust it. And [music] his story is the reason I am telling you instead of selling you. His name was Earl Henson and he lived in a single-wide trailer on the eastern edge of Lancaster County, Pennsylvania, about 4 miles south of the village of Bird-in-Hand on a gravel lane that did not appear on any map I could find in 1994. He had been a mechanic for the Pennsylvania Railroad until they shut down the Lancaster Yard in 1976. And after that, he worked on tractors, lawn mowers, >> [music] >> and the occasional diesel pickup for anyone who knocked on his door. He charged what people could pay. Sometimes that was $12. Sometimes that was a jar of pickled beets. He did not care. He was 71 years old when I met him and he had a 1978 Mercury Marquis that he'd been driving for 16 years. And that car, by his own measurement with a notebook he kept under the driver seat, was getting 34 miles to the gallon on the highway. A 1978 Mercury Marquis, a car that came from the factory rated at 14 miles per gallon. He had more than doubled it, and he had been doing it since 1981. And he learned it from a man named Walter Yoder, who learned it from his father, who learned it during the rubber and fuel rationing of the Second World War, when every gallon of gasoline in this country had to be stretched because the tankers were being sunk by German submarines off the coast of New Jersey, and ordinary Americans were figuring out in their barns and their garages how to get more out of less.
That is the lineage of what I just gave you. It is not some trick somebody invented last Tuesday on a forum. It is a piece of working knowledge that came out of a national emergency, was preserved by people who lived through that emergency, was passed down through families that did not throw anything away and did not trust anyone in a suit, and was systematically erased from the public mind the moment the war ended and Detroit decided that the future was bigger engines, bigger cars, and customers who would never again think about what was actually happening inside their fuel system.
Earl Henson kept it alive in a notebook under the driver seat of a Mercury. Walter Yoder kept it alive in a stable behind his house. And there were thousands of other men in Ohio and Indiana and Iowa and upstate New York and the hill country of Tennessee [music] who kept it alive the same way. Quietly, without fanfare, without trying to sell it to anyone, because they understood that the moment you try to sell something like this, the people who profit from the opposite will come for you.
And they did come. I want to tell you about a man named Charles Nelson Pogue, because his story is the warning that hangs over everything I am telling you tonight. Pogue was a Canadian inventor from Winnipeg, Manitoba, and in 1936 he patented a carburetor design. United States patent number 1,750,354 was actually one of his earlier ones, but the famous one was patent 2,026,798 that he claimed could deliver over 200 miles per gallon on a standard Ford 5/8 engine of that era. 200 miles per gallon. The newspapers covered it. The Winnipeg Free Press ran a story on it. Popular Science wrote about variations of the design. Ford Motor Company sent engineers to look at it. And then, somewhere between 1936 and 1938, Charles Nelson Pogue stopped giving interviews, stopped demonstrating the carburetor, and quietly went to work for a company called Economy Carburetor Limited, which was bought and then bought again, and then dissolved. And the patent sat on a shelf, and the man who had once been on the front page of newspapers across North America died in 1985 in relative obscurity, and [music] his carburetor was never put into production on any vehicle that you or I could buy. His widow, when asked about it years later, said only that her husband had been told it would be better for everyone if he stopped talking. Better for everyone. Think about what that phrase means when it comes from someone who has just been visited by representatives of an industry that makes its money selling you fuel.
I am not telling you that Pogue's 200 miles per gallon was real. I do not know if it was. >> [music] >> What I am telling you is that the pattern of suppression around fuel economy in this country goes back almost a century [music] and it is not paranoia to notice it. Because the documentation is there in the patent office, in the old newspaper archives, in the records of the Federal Trade Commission investigations of the 1930s into what was [music] called at the time the gasoline trust. There were congressional hearings in 1936 about price fixing among the major oil refiners. There were settlement agreements signed by Standard Oil of Indiana, by Shell, by Texaco, by Sinclair in which they agreed to certain practices going forward >> [music] >> and paid certain fines. And in the middle of all of that, a quiet little patent for a fuel additive that increased mileage was approved, ignored, and forgotten. I have a photocopy of that patent on the wall above my desk. It is dated the 14th of November, 1939. The inventor's name is on it. >> [music] >> I am not going to say his name on this video because I respect his descendants and I have been asked by one of them politely [music] not to. But the patent is real. The chemistry is in it. And the chemistry is essentially what I just walked you through.
Now, I want to address the objections because I know they are coming and I would rather answer them here on the record than pretend they do not exist.
The first objection is from the engineers, the real ones, the ones who actually went to school for this. They will tell you that the energy content of gasoline is fixed at approximately 114,000 British thermal units per gallon and that no additive can change that number. And they are correct. The energy in the fuel is the energy in the fuel. What the additive does is not add energy. It changes how much of that energy actually reaches the wheels of your car instead of being wasted as heat, as unburned hydrocarbons going out the tailpipe, as friction in the upper cylinder, as carbon deposits that progressively choke off the proper flow of air and fuel through the intake. A modern gasoline engine, even a good one, even a new one off the showroom floor in 2024, only converts about 25% [music] of the energy in the fuel into actual forward motion. The rest is lost. [music] If you can recover even 10% of what is currently being lost, you have effectively increased your miles per gallon by a third or more without changing the energy content of the fuel by a single BTU. That is what is happening here. The engineers are right about the physics. They are wrong about the conclusion because they are answering a question I did not ask.
The second objection is from the warranty people. They will tell you that putting anything into your fuel tank other than the recommended fuel can void your manufacturer's warranty. This is technically true, and you should know it. If your car is under warranty and something goes wrong with your fuel system and the dealer pulls a sample from your tank and sends it to a lab and finds anything unusual in it, they can deny the claim. I am not telling you what to do. I am telling you what Earl Hanson did and what Walter Yoder did and what the patent from 1939 describes. The decision is yours. I will say this: the components I described to you in the proportions I described [music] are at concentrations well below what any standard fuel system test would [music] flag as contamination because they break down completely during combustion and leave essentially nothing behind that a lab technician would not also find in commercially blended pump gasoline. The acetone is gone, the xylene is gone, the mineral oil contributes a trace residue that is chemically indistinguishable [music] from the residue left by every other engine on the road. I am not a lawyer. I am not your lawyer. I am telling you what the chemistry says.
The third objection is from the safety crowd, and this one I take seriously. Acetone is flammable. Xylene is flammable. Mineral oil is not, but the other two are. You are mixing them in your garage in a glass jar near a car. You need to be smart. You do not smoke while you are doing this. You do not have an open flame within 15 ft. You do not store the mix jar in direct sunlight or near the water heater in your basement. You label it. You keep it out of reach of children. You wash your hands when you are done. These are not complicated rules, but I have to say them because somewhere out there is a person who will not think of them on his own, and I do not want that person to be hurt. Treat it the way your grandfather treated the can of gasoline he kept for the lawn mower. With respect, with attention, and with the basic awareness that fire is a thing that exists in the world.
The fourth objection is from the environmental side, and I want to address this one honestly because I think a lot of you care about it, and you should. The mixture I described, when it burns inside your engine, does not produce more emissions than gasoline alone. In most measurable categories, it produces less. The cleaner combustion means fewer unburned hydrocarbons going out the tailpipe. The lower carbon deposits over time mean your catalytic converter works more efficiently for longer. The improved fuel economy means you are simply buying less gasoline overall, and burning less gasoline means less carbon dioxide entering the atmosphere per mile driven. The only category where you might see a slight uptick is in certain volatile organic compound measurements taken at the tank itself during refueling because the xylene has a higher vapor pressure than some grades of gasoline. That is a real thing. It is also small enough that it does not meaningfully change your contribution to anything. If you are the kind of person who cares about your footprint, this practice is on balance better for the planet than what you are currently doing. That is the truth as I understand it based on the chemistry and the combustion data.
The fifth objection is from the people who have tried something similar and gotten poor results. I hear from these people all the time. They write to me. They tell me they tried acetone alone, or they tried it at the wrong ratio, or they tried it in a vehicle with a known issue like a stuck thermostat or worn oxygen sensors, and they did not see the improvement they were hoping for. And what I tell them every time is that the three components work together, not separately. Acetone alone will give you a small improvement, maybe 4 or 5%. Xylene alone will give you a small improvement in a different part of the combustion cycle. Mineral oil alone will give you almost nothing measurable in the short term, although your upper cylinders will thank you over the long term. It is the combination in the proportions Earl Hensley worked out over years of trial and error and that Walter Yoder confirmed in his own engines before him that produces the doubling effect. You cannot leave one out and expect the same result. You cannot substitute one for something else and expect the same result. The chemistry is specific, the ratios are specific. The reason it took so long for ordinary people to rediscover this is that it is not obvious from any single ingredient. It only works as a system.
Let me give you a few more specific numbers from drivers who have written to me over the past 2 years because I think the range of results tells you more than any single average could. A man named Dale in Kingman, Arizona driving a 2007 Chevy Silverado with the 5.3 L V8 was getting 15 miles per gallon on his regular commute. After 30 days on the additive, his commute number was 28. A woman named Patricia in Watertown, New York driving a 2014 Honda CRV was getting 26 miles per gallon in mixed driving. After 3 weeks, she was at 41. A retired diesel mechanic in Owensboro, Kentucky named Marvin put a modified version of the mixture into his 2003 Ford F-250 with the 7.3 L Powerstroke diesel and reported going from 16 miles per gallon on the highway to 26. Diesel is a different chemistry and the mixture has to be adjusted for it, which I will explain in another video, but the principle holds. The combustion is incomplete. The additive helps complete it. The mileage improves.
Now, not everyone doubles. I want to be honest about that. The average of the responses I have received, and I have received over 4,000 of them at this point, is an improvement of about 68% over baseline mileage. That is not doubling. That is less than doubling, but it is also dramatically more than what any commercial fuel system cleaner or octane booster on the market today can deliver. And those products cost between $9 and $22 a bottle and give you at best a 3 to 5% improvement that fades within a single tank. The people who get the full doubling effect tend to be driving older vehicles, vehicles with carbureted engines or early fuel injection systems, [music] vehicles that have been driven hard and have significant carbon build-up that the additive can address. The people who get the 60 to 70% improvement tend to be driving newer vehicles that were already running cleaner. Either way, the improvement is real, it is measurable, and it pays for itself within the first tank of fuel.
I want to take a moment and tell you what Earl Henson said to me the last time I saw him, which was in October of 1996, about 6 months before he passed away. He was sitting on the porch of that single-wide trailer with a cup of coffee that had gone cold an hour earlier, and he was looking out at the field across the road where a neighbor was running a corn picker, and he said to me, without me asking, he said, "The thing you have to understand, son, is that they do not need to hide it from you. They just need to make you think it is too complicated to bother with. >> [music] >> They need to make you believe that the smart people have already figured all of this out, and that there is nothing left for a man like you to discover in his own garage. The day you stop believing that is the day you take your money back." That is what he said.
He died in April of 1997. His Mercury was still running. His daughter inherited it, drove it for another 6 years, and finally sold it to a collector in Maryland for $1,800 in 2003. As far as I know, it is still on the road. >> [music] >> The notebook under the seat went with it. I think about Earl when I get the emails from people telling me this worked for them. I think about Walter Yoder, who I never met, but whose name comes up in three different patent applications from the 1950s that I have managed to track down in the archives. All of them for variations on fuel system improvements, none of them ever commercialized. I think about Charles Nelson Pogue dying alone in Winnipeg in 1985 with a patent on his wall that no one would let him build. I think about all the other men and women whose names I will never know, who kept [music] this kind of practical knowledge alive in the margins of American life, in the barns and the garages and the small repair shops on the outskirts of small towns, while the big companies in Detroit and Houston and New York built an entire economy around making sure you never thought to ask the question they did not want answered.
The question is simple. How much of what you are paying for is actually being used? The answer, in the case of the gasoline in your tank, is somewhere between a quarter and a third. The rest is [music] being wasted. And you are paying for that waste every time you stop at the pump, every week, every month, [music] every year for your entire driving life. Over the course of a 40-year driving career, the average American will spend approximately $140,000 on gasoline in today's dollars >> [music] >> and roughly 2/3 of that money, which is to say about $93,000, will be spent on fuel that never actually moved the car forward. It will be spent on heat, on friction, on unburned exhaust, on carbon deposits, on the inefficiencies of a combustion process that has been kept just inefficient enough to keep you coming back to the pump. $93,000 per driver. Multiply that by 230 million licensed drivers in this country and you start to understand the scale of what is at stake. And you start to understand why a simple $3 additive that recovers even a fraction of that loss is the kind of thing that does not get talked about on the evening news.
I am going to leave you with one more thought before I sign off. And it is this: the knowledge I just gave you is not mine. I did not invent it. I did not discover it. I am only the person who happened to be in the right places at the right times to hear it from the people who did, and to write it down, and to verify it in my own vehicles, and to share it with you. If this video gets taken down, if [music] this channel disappears tomorrow, if I get a letter from some attorney telling me to stop, the knowledge will still exist because you have it now >> [music] >> and you can share it with the people who matter to you. Your father, your brother, the neighbor down the street [music] who is struggling to make his truck payment and his fuel bill in the same month, the young couple at your church who just bought their first house and cannot figure out why every paycheck disappears before the next one arrives. Tell them, show them, walk them through it the way I just walked you through it. That is how this stays alive. [music] That is how it has stayed alive for the last 80 years through the rationing of the Second World War, through the oil shocks of the 1970s, through every recession and every spike in pump prices and every promise from every politician that relief was just around the corner. It stayed alive because ordinary people told other ordinary people in kitchens and on porches and in the bays of small repair shops. And they did not wait for permission, and they did not ask whether it was allowed.
Try it this weekend. 2 and 1/2 oz in 10 gallons, drive your normal route, write down the before number and the after number, come back here and tell me what you found. And then tell somebody else. That is the whole assignment. That is the whole point of all of this. Take back what was taken, pass it on to someone who needs it. And remember, the next time you are standing at the pump watching those numbers spin past $60, that you are not standing there because you have to. You are standing there because somebody a long time ago decided you should never know any better. And now you do.
Subscribe, share this with one person who would benefit from it. I will see you next week with the rock salt and copper trick that has been keeping Amish basements dry since before electricity reached those farms. Until then, drive smart, measure everything, and trust the old knowledge. It has not let us down yet.