February 1, 2023

Does fuel really matter for your engine? Watch as the Engine Masters team takes a scientific look at just how much power and performance are produced by different types of gasoline.

You made me do this seriously since the very beginning of the engine masters show the audience has demanded a showdown of like low octane pump gas versus better pump gas versus race gas what does it all mean to you so here’s what we’re gonna do we’re gonna run 87 versus 91 octane california pump gas straight out of the station down the street and then we’re going to

Run sunoco leaded race gas in 110 octane and 116 and at the very end yes we’ll be running e85 to find out if it makes even more power than gasoline here’s the engine that we’re going to be doing it with this is a blueprint engine’s crate motor it’s an ls3 it’s a 6.2 liter it’s got blueprints 259 heads on it it’s 10.7 to 1 compression it has a 225 239 camshaft in it

Obviously a hydraulic roller it’s advertised at 530 horsepower and 495 pound-feet of torque we’re still testing with the 87 octane pump gas and we’ve done our timing sweeps we found that 29 degrees of total ignition timing is kind of the optimum in this circumstance the next thing that we’re going to do is test air fuel ratio we’re gonna swing it a little bit

Leaner half a point leaner half a point richer and see if we see any trend there all right first pass is going to be half a point richer sure enough it’s just a little bit tiny tiny bit down when it’s half a ratio rich so now we’re gonna go half a ratio leaner than it was on our baseline so so it looks like our best pull is going to be 29 degrees of ignition

Timing and 12.8 to 12.9 afr what a surprise i know kind of right there so our power numbers for this thing actually dead on what blueprint engines advertises are pretty close 539.4 horsepower at 6400 rpm 498.9 pound-feet of torque at 5200. the other thing that i’m going to do in this episode is run average power in case there are changes at other points in the

Curve with the different gasolines and we did that from 3 500 to 6 500 rpm so add up all of the power numbers divide by the number of data points and here’s what you get 475.5 pound-feet on average and 452.7 horsepower on average so the takeaway for me is under dyno conditions the 87 octane met the engine’s requirements because it all came out in the normal range

Of timing and air fuel i still think if it was me i wouldn’t do it in a car no hotter temperature in the coolant more load more under hood temperature worse manifold air temperature i’m not going to do it all that stuff you just said is all bad um you know in the dyno cell we’ve got good air flow we can keep the engine cooler just it it all makes it easier and

Kind of helps suppress detonation under the hood whole different story yep right okay so we’re in agreement ready to move on to 91 octane pump gas so here’s our final data with 91 octane pump gas we found that it wanted the same ignition timing as the 87 octane 29 degrees what’s really interesting is that it ended up wanting to run a little bit leaner we saw

About 13 and a half to one made microscopically more power than 12.8 to one i’m talking like two or three numbers here or there but it was better and so we ran the thing a little bit lean here’s our peak power numbers horsepower 539.6 at 6400 rpm torque 501.1 at 5300 rpm now that 501 seems like we crested the 500 number on torque well we were running 498.9 before

So it’s very very little as evidenced by the average power numbers which are this keeping in mind this is 3500 to 6500 rpm we saw 476.3 pound-feet of torque and 453.6 horsepower which is like insignificantly higher i see average people go oh should i get the 87 or should i get more power out of the 91 in fact some of the gas is advertised as like you know super

Power 91 or whatever and the fact is at the pump if your engine’s not in detonation at 87 octane it’s not gonna make more power at 91 octane do you think that’s a fair categoric statement i think that’s a pretty fair statement across the board if it doesn’t need the octane it doesn’t need the octane yep and so now we’re going to go to the sunoco 110 octane leaded

Race fuel this is going to be the 91 octane unleaded coming out and 110 octane leaded race gas going in so we’ve gone through our whole tune-up plan on the 110 and big surprise it still likes 29 degrees of timing no difference at all and the afr it went back to what we saw with the 87 octane which was that it really likes 12.7 to 12.8 at peak power here’s the

Power peaks 539.9 horsepower at 6400 rpm and the torque 499.1 at 5300. on our averages 475.1 pound-feet of torque and 452.5 horsepower so once again nada all right that’s all of the sunoco 110 out and now troy is going to pour the 116 in okay steve i apologize for wasting your time that’s been a whole lot of dino bowls to figure out it doesn’t care guess

What 116 octane likes 29 degrees of timing just like every other fuel and uh pretty much 12.8 to 1 afr also here’s the power peaks with the 116 they’ll sound surprisingly familiar to you 541.3 horsepower at 6 400 rpm 497.4 pound-feet of torque at 5300 rpm on average 474.7 pound-feet and 452.1 horsepower which is less than one horsepower on average different than

The 87 octane i guess uh gasoline’s gasoline exactly it’s all the same i think we would all agree that the results would be wildly different if this was boosted or had 14 to 1 compression or anything like that for an engine like this the bottom line conclusion is if you don’t have a knocking problem with the fuel that you’re running now more octane is not going

To make more power 100 agree so now we have to find out if e85 makes more power as we drain the gasoline out of our ls3 and load it up with some ethanol mix so on that one you actually swung the timing all the way to 33 right yeah because well i’ve heard the the e85 guys say oh no you gotta add six degrees you gotta add eight degrees i mean i’ve heard like some

Crazy timing numbers so i wanted to go past where we lost a little power to show that if we went further we lost more so we went over the edge oddly enough it still wanted the same timing that it had yep that’s what we found 29 degrees of timing again the same as the gasoline made the best power on e85 now the air fuel ratio of course we also tuned it all over the

Place and we found that on a gasoline scale at like 12.6 to 1 on a lambda scale actually for e85 that would be an 8.4 to 1 air fuel ratio here’s the peak power numbers finally we’re seeing some improvements 551.5 horsepower at 6400 rpm the torque 506.5 at 5200 rpm we also took our averages which is another big jump up the torque was 484 and the horsepower 460.9 so

Those are good gains i like the 75. yeah can we look at the overlay of this which gasoline do you want to run it against 91 is probably just fractionally the best gasoline show the 91 so that would be like pump gas to pump gas what a normal guy could do meaning 91 to e85 so this overlay is going to tell you how much better the e85 is wow okay that’s unusual based

On what we’ve seen before we did an episode with a 12 and a half to one big block with a carburetor and we did e85 versus race gas and it made meat in the middle had improvements right in the middle of the curve but nothing at the top this surprises me too i thought maybe with a little more time down low to cool the combustion chamber we might see bigger changes

There but man it’s just railroad tracks all the way up it just makes more power it’s got oxygen in it more oxygen in it hmm not what i expected but still pretty good i mean it’s obvious why people run e85 and this isn’t even boosted we know it boosted applications it makes a way bigger difference it made more power but really its major advantage is its octane and

Detonation tolerance because you can run a lot more compression ratio n a than we have here or like you said a boosted application you can run more boost with uh that fuel because it cools the intake charge i guess we need to move on to methanol now when we do that what is the difference between the stoic of e85 and stoichiometric for methanol six six and nine to

One for the e85 which means speaking in broad terms methanol wants about twice as much volume of fuel as gasoline 100 more instead of 30 percent more right and it wants another 30 on top of e85 more than that more than that yeah i mean if you’re starting with you know 100 pounds and you turn it to 130 pounds if it’s 30 percent more a hundred percent more isn’t

30 another 30 is it 30 of a hundred i always screw up the math when we get why would you say twice as much well but how much more do you need how much more fuel do you need to go from gasoline to e85 30 okay and from going from gasoline to methanol you need a hundred percent more you double it yeah which is why you can’t take an e85 carburetor and turn it into

A methanol carburetor have you looked at methanol carburetor jets yeah they’re like you know it’s a whole other jet configuration a whole nother thread count a whole nother metering block the orifices throughout the carburetor are massive so it’s it’s built to move a lot more fuel well let’s find out if it’s worth it so we’re going to go change the carburetor to

A qft methanol carb and then pour methanol in the tank and fire it up and see if that methanol is worth way more power is it worth the aggravation that’s we’re here to find out do look at this packaging it’s like nice and blue i like methanol power oh yeah methanol is best really if it’s right for your application though you’ve always told me that it

Makes more torque than horsepower but let’s have a look here’s our power numbers on the methanol way more torque we got 670 pound feet if you compare that to regular gasoline at 647 that’s a big change and our horsepower was 769.6 up at 6 500 rpm which is almost the same we saw 770.4 on the gasoline so while that looks fantastic it’s basically the same as the

Oxygenated gasoline yeah let’s go into pros and cons of methanol i think it has some big cons again that is what stops me from considering it useful the problem with methanol is you have to service the fuel system anytime you’re going to park the car that’s because of that it’s corrosive it’s corrosive it’s hygroscopic so it pulls water in and then corrodes

Everything here’s a question because i know that like on a top alcohol funny car it just destroys the oil on every pass yeah does that happen if you’re using it on a boat if you’re making that kind of power yeah i mean but i think a lot of that has to do with when you’re running 30 pounds of boost you’re pushing something past the rings no matter what every single

Time so maybe with less boost or normally aspirated you’re not going to have those problems to that extreme the other thing is that it’s harder to ignite have you run across a situation where you need more ignition system than you would for gasoline if you’re running in methanol not so much more ignition system because it seems with the msd stuff we’re kind of

Okay with most of all that stuff anyway what i have seen though is it’s a little harder to ignite and so we have to run a higher engine temperature get it to get it to vaporize sometimes yeah you’ve got to run higher engine temperature so it vaporizes yeah yeah how about if the ignition’s got like four spark plugs completely knocked out of it well that that slows

Things down just a bit but see that again the msd kept firing past thank you um and the pros for it obviously dirt cheap yes makes power so basically i’d say if you’re a guy on pump gas don’t worry about any of this you might want to run e85 it’ll give you a little bit more power on your naturally aspirated deal if you’ve got compression man this oxygenated fuel

Is an eye opener that’s going to give you another 10th or something put you just over the edge of where you need to be if you’re running boost just go to the alcohol that’s it right done done all right firm answers which rarely happens on any episode of asian masters you

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Does the Fuel You Choose Matter? | Engine Masters | MotorTrend By MotorTrend Channel