6G Celicas Forums

This past weekend, I encountered a scenario that got me thinking about ethanol in gasoline again- is it hurting vehicle performance? It all started with a trip over to Wisconsin. On the way home, I had to fill the car up, so I pulled into a station just before I crossed back into MN. I've been filling my car up with premium fuel for quite some time, as I have always felt that it's made a difference in the performance of my car, even more so now that my car has 185,000 miles and has lost a lot of its original power. I noticed that the station I was at had premium fuel that was rated at 91 octane. Typically at home, the station I frequent sells 92, so immediately I thought to myself that I may notice a difference and experience decreased performance. I certainly did not expect it to make the difference that it did. There was a very noticeable improvement in the power that car was putting out! Now that I’ve used up half the tank and have seen that this wasn't a fluke, I started to ask myself why this particular tank of gas was making that difference, and it occurred to me just now.

Here in MN, it's been law for years that all gasoline sold in the state be at least 10% ethanol. After some research, I found that in WI, gasoline that is 91 octane or higher does not have this similar requirement. I then decided to read up on ethanol gasoline blends. I found that for ethanol blends to be used efficiently, the engine burning the blend should have higher fuel injection pressure or larger injectors than that of an engine that runs on gasoline alone, thus explaining why the ethanol-free gas in my car is "creating" more power... Annoying! This is also why only EFI engines can tolerate ethanol blended fuel without re-tuning of various parts of an engine's fuel supply system (cars without electronic oxygen sensors cannot compensate for the difference in energy the fuel contains. I'd also argue that some EFI systems, like our older ones, don't do a good job of adjusting, either. Most vehicles in the USA can only tolerate up to a 90/10 % split without big problems). More discouraging facts: ethanol blends have larger amounts of water in them compared to gasoline, and they also contribute to accelerated engine wear thanks to the "drying" effect alcohol has...

All this info makes me suspect that my car isn't as tired and worn out as I once thought. I'm now thinking it's the gas blends we are required to use in this state. For those of you who have easy access to ethanol-free gasoline, I'd strongly recommend selecting that choice over the blend.

you are imagining all of it in your head

you don't feel the difference of 1 point

also premium in your car = waste o money

This post has been edited by playr158: Jul 14, 2008 - 11:20 AM

I agree. Premium is useless in our cars. Unless your running a 3S.

Whatever you guys say. I'm with Saleeka - I too have access to both and I have also felt the difference.

you do know higher octane gas...the only difference between 91oct. and 87oct. is that 91oct. is HARDER to burn...thus less likey to give your little gt any performance.

I think that this is an oversimplification because it doesn’t take into consideration the energy content of the fuel itself (something the octane rating doesn’t measure). Ethanol blend has less energy in comparison to regular gasoline, so having a higher octane rating makes the fuel more controllable, so to speak, and in turn you can extract more energy from that fuel. I haven't been able to compare "normal" gasoline in varying octane ratings to be able to agree or disagree with you, but when it comes to E10, I have noticed a power difference with different octane ratings, and in particular at higher RPMS. Throttle response with 87 rated E10 versus 91 rated "gasoline" is like comparing night and day...

Ethanol in gasoline does hurt performance, and gas mileage. However, I haven't seen any 100% gas in years. If I had the choice, I'd go with the 100%. But it's probably more money, and who knows if it's worth it. I don't see the point though, your brain can easily create feelings of it being peppier.

This post has been edited by Supersprynt: Jul 14, 2008 - 3:48 PM

Who's GT? No 5S here.


I'm totally in agreement but then there were days when all I wanted was to get to work on time and my mind was far from E10 vs Straight Gasoline and it would remind me via butt dyno. IDK - I'm not saying I'm any kind of expert but I can agree with Saleeka - I swear I can feel a difference. See, here in Houston we are fortunate/unfortunate enough to have E10 in town at the pumps but leave the city and go to the next large town down the highway [Brenham] where my GF lived for a while and they have no ethanol content [Possibly due to the high amounts of older Carbureted vehicles there? IDK. They also have no emissions testing where as we have one of the strictest in the country].
Who knows - maybe it is all in our heads - that's why normally I don't pipe up when this conversation comes up but Saleeka's story sounded just like what I noticed in my own wanderings and I find myself believing there must be some merit to it. Is there nowhere you can still get straight Gasoline?

This post has been edited by DEATH: Jul 14, 2008 - 6:28 PM

Wow i cant believe so many people are talking about E85 in cars that are not made for it. If your car is made for it... great use it! If not DON"T! Its that simple, there r various reasons why u can hurt your car with E85 (see me post here http://www.6gc.net/forums/index.php?showtopic=59989). But your are not getting better performance or more HP PERIOD. Unless your engine has something like 12.7:1 compression you will see no extra power. And when people say "well my car seems to run smoother" or course it does one inherently bad property of E85 is that is act like a solvent and eats up carbon then your seals and aluminum. Best thing is use one tank of E85 it will clean your car and restore (not add) some power, then go right back to whatever your OEM says to use. Also with the much higher octane u would need to adjust timing or even get plugs with a different heat range. And E85 is not "harder" to burn once ignited is burns more rapidly, its just harder to ignite in the first place. If u guys r so concerned about MPG just do the basic stuff 90% of people over look. Clean you air filter often, change your oil, keep your tires inflated properly and don't carry around that set of golf clubs and the bowling ball all week when u only bowl and golf on the weekend!

There's E85, which is ethanol with 15 per cent gasoline, and then there's ethanol-blended, which is gasoline with some quantity (usually less than 15 per cent) of ethanol.

E85 requires a fuel system with nitrile rather than rubber for hoses and the like, as it can eat some materials. Most vehicles since the mid-1990s have a fuel system which can withstand ethanol in the gas, but E85 requires a little more work. E85 contains less energy per litre, meaning you will get lower MPG, but it burns cleaner. E85's corrosive properties will also break down deposits which have built up on injectors, often leading to the fuel system failing -- it's not the fuel, it's all the crap you built up in your fuel system over the years, which is why switching is generally not recommended for older cars without extensive preparation.

E85 and gas can be run on the same vehicle, but this requires some extra engineering. Actually, this is a way the domestics get around fleet emission requirements; they make large-engine vehicles flex-fuel capable and claim their fleets are cleaner, but know that 90 per cent of those vehicles will never see E85.

hallelujah!

but i like my golf clubs do i have to take them out?! can't i just like remove like a piston or something?!

Well i don't know about ethanol but if you have eropean or jdm engine then it's totally understandable that your car runs better with higher octane since they arent designed for US low octane your max octane is minium here in europe so no wonder if DEATHs jdm 3sgte runs better because i recall that japan has same octanes as europe, but if you'd compare 95(your 91) wich is minium here and max 100octane there's no difference.

So in other words if you have 5s i belive your mind made a tricks with you but if that's 3s then you're most likelly right and your car is running better.

just keep the putter in the car for practice, the short game is where everyone adds a bunch of strokes anyway.