Fuel Octane Level on Performance

[Tornado1M]

So, there is a thread over on the M2C Forum about an owner who picked up his car in Europe and came back to the States.

However, when he returned, he felt the car did not perform like it did when it was in Germany?

The issue of Gas Quality came into play?

So, I wanted to discuss here if anyone has felt a difference with gas quality and octane rating from 91 to 94 with or without 10% Ethanol and/or Flexfuel?

This is around my area, have not tried it and I'm not sure it's ok to try???

[1'M Blue]

Im not sure about the 1M but in general, I feel most if not all, sports cars do get affected with noticeble differeces when there is a varying level of feul octanes being used.

[nachob]

I did Euro delivery and my 1M felt faster in Europe but not sure if it was because it was new to me. With that said I believe Europe and US use different rating methods so it's not equivalent. Performance would drop if the car detects pinging but 91 should be enough to prevent it unless you got bad gas. I don't believe 91 or European 94 would make that much difference unless you were in high heat or track where detonation can increase. I have owned two 1Ms and have driven them in Europe, Canada and the US. Even with 91 octane I have always found the power delivery in the 1M to be slightly unpredicable. On cold morning, it is a monster and warmer days it's more tame. I have gotten pretty used to the power but every now and then the universe aligns with the right 2nd gear, rev range, temperature and who knows what else where the car catches me offguard and launches like a 400hp beast. It has happened to me a few times where everything is right. The traction control doesn't bog down the tires are up to temp and motor is in some sweet spot.

I don't think the difference is performance is 91 vs 94 euro or higher. I think the nature of these motors coupled with traction control, temperature makes the delivery vary slightly.

With that said, bad gas that has been diluted can reduce performance but once you are in the 91 US range, you are fine and more octane will not due anything unless on the track or death valley in summer where detonation can happen due to heat issues.

I have heard that gas stations order a set amount of regular unleaded and if the their underground tank fills up, the dump the remainder into the premium tank since they bought it already. Europe has more consumer controls than US so it might happen less there but that is possibility here.

That's my two cents worth.

Here is article from The Economist on octane. They state that 94 euro is equivalent to US 91 . Also that the US standard is more comprehensive than the RON Europe one. https://www.economist.com/babbage/20...-needs-premium

[Tornado1M]

I've never heard of them dumping Regular into Premium??? WTF!!! That's insane! Does this really happen?

[nachob]

Originally Posted by Tornado1M

I've never heard of them dumping Regular into Premium??? WTF!!! That's insane! Does this really happen?

I have heard that but not seen it myself. If they have extra they can't send it back it has to go somewhere so they put it wherever they can. If anyone here knows firsthand let us know. Otherwise these motors deliver power inconsistently based on a lot of variables and iffy gas can impact performance but good 91 US and good 94 euro are pretty much the same.

[Win]

I'm pretty sure your car has to be designated flex fuel to use that gas (yellow pump)

You can find "race gas" 98-100 octane at the rare station

Canada offers higher octane at almost every station than the US offers. Read there's legislation in the states to do similar because it's a win-win for all sides.

And yes, US gas is crap quality. I remember 60 Minutes covered a study taking random samples of gas at stations across all states and the results were shocking... some pumps even had gas that wasn't even the right color, like brown. Scary.

[nachob]

Originally Posted by Win

I'm pretty sure your car has to be designated flex fuel to use that gas (yellow pump)

You can find "race gas" 98-100 octane at the rare station

Canada offers higher octane at almost every station than the US offers. Read there's legislation in the states to do similar because it's a win-win for all sides.

And yes, US gas is crap quality. I remember 60 Minutes covered a study taking random samples of gas at stations across all states and the results were shocking... some pumps even had gas that wasn't even the right color, like brown. Scary.

Yes, I looked up to see if I could find about gas stations putting the remainder of their regular in premium and it says that sometimes the gas station doesn't even know. The distributor car rip them off and put regular in premium. But what I found out was that contamination and degradation is probably more common. Here is a NBC report on contamination and lack of government checks on fuel quality.

https://www.nbcnews.com/business/con...-think-n776016

As I said above, 91 octane of good quality should be equivalent to euro 94 octane since the rating methods are different. This also applies to fuel. When comparing octane ratings, check to see which rating it is. RON, MON or AKI. They are not all the same.

Finally, octane rating is not necessarily better. Ethanol fuel can have a higher octane rating but might not play well with your car. It burns with less energy than petrol which means you end up pushing the gas pedal more and end up using more gas in some cases.

Finally, when I worked for Nissan's GTP program in the 90s, we used race fuel that worked great on 3 hour races. We won 4 IMSA manufacturer championships but we experienced quick fuel injector degradation. We researched it and found Techron to help clean the injectors after every race but we always wondered why the clogged so quickly. Then we went to Le Mans and our cars were leading for a long time only to DNF when the fuel cells disintegrated on us. I don't recall if they just blamed the fuel cell manufacturer but they basically fell apart with the glue that holds the bladder coming apart. Our "race" fuel had high levels on Toluene which is what old school model airplane glue that melted plastic is made of so just think twice before putting "Race" fuel in your BMW that BMW says can't even handle american Sulfur content.