Regular or Premium fuel? [merged]

[Eclipse_98_RS]

Hi guys, my car is an all-stock RS, but I'm going to start doing some mods to it. Right now I just use regular unleaded gas, but when should I start going up in the octane? After intake/exhaust, or beyond that? I don't want to screw up my engine but I don't want to have to shell out more cash on fuel than I do now. I know, I'm a cheap bastage.

 

[denniegst]

On one two hour trip, "drafting" behind a friend's Jeep, I got over 30mpg.

how do you 'draft' behind someone?

 

[brute]

You let their car break the air resistance so that your car does not have to. You basically just drive close behind them. Air will no longer be working against you. I used to do this with my Camry because I'd constantly run it on 1/4 tank or less. I'd draft behind semi trucks... they usually get pretty mad though, and it's dangerous because you don't know what the driver in front of you is going to do.

In my Galant, I've been doing many mpg tests. All highway driving, getting on it when I need to pass someone, I get ~24. Or, I can be all gas / all brake and still get about 22-23. So it's always 23-24 for me.

 

[Eclipse98_RS]

i get 30 MPG in my 2g eclipse GS-T on the highway. I used to have a 98 RS hence my name,
and i got 38MPG once with octane boost and injector cleaner. Suppose it depends on how you drive... If you go WOT all the time your gonna see some crappy numbers for mileage, and if you drive like a grandma then you might squeeze a few extra mpg out of your tank. As far as running anything less than premium... unless you have a non turbo run premo. i dont know enough about race gas to say anything about it.

 

[mattspyder]

I know our turbo cars say premium fuel only but is everyone really running this with the price of it. It is almost $3.30.

Just curious?

 

[AWDtsi1995]

I put premium in mine and always will no matter the price. Doesnt the car run like crap if we put any lower?

 

[Cs4g63]

I run premium and its supposed to hit over $4.00 with no problem this summer. At least its possible to get fairly decent gas mileage in a DSM.

 

[Loco4Life]

89 octane will be devastating to your car. These gas prices are killer though.

 

[Talesin]

$3.60 already out here, and that's for CA 91 craptane. And yes, never run mid or bottom-grade. Soon as you hit boost you'll start to knock, or if you go with REALLY crappy gas, outright detonate. You'll also be likely to screw up the fuel trims in the ECU. Hoping to find someplace around here selling 93+, and will gladly shell out $4-5/gal for the extra points.

Rocket rides have an entrance fee. Start cutting that, and... well. Might as well buy a crappy Honda to use as a runabout, if the $0.20/gallon difference in cost of fuel is an issue, and only take the DSM out when you want to actually enjoy driving.

It's the difference between a $49 fill-up, and a $51.80 fill up, assuming 14 gallons. Three bucks. Is saving three dollars worth potentially blowing your engine, or at the very least gumming it up and causing undue wear and tear? Hell, back when it was $1.50/gal for the cheap stuff and $1.70 for premium it was a valid consideration. That twenty cents was a much bigger relative hike. But looking at the jump between $3.50 and $3.70? Pfft. Pocket change in comparison to the overall price.

 

[staticbrainwash]

I get 93octane for 3.10 ish. Was about 2.89 for a while, but jumped up again. I'd gladly pay whatever i need to to make sure i don't blow up my car. And hell, if gas gets too expensive, i'll go to the local small airport and get 100-110 low-led for less than 4 bucks!

DO NOT skimp on gas, just cruise less, drive slower, or tune your car better. Don't risk it.

 

[gsx951]

Can"t you get E-85 dirt cheap in Wisconsin?
Do a search here for E85

 

[mattspyder]

E85 gas huh Ill have to do a search on that and let you know, thanks for the tip on that

 

[jiggysnitz]

What gas stations do you find 93 at? I thought we got pretty good gas up here in washington but the best I have found so far is 92 from shell.

 

[mattspyder]

About the E-85 gas stations, Yes we do have it hear in wisconsin and there is a station about 30 minutes away from my house. its going for alittle over 2 bucks.

PLEASE tell me we can put e-85 in our cars.. please please please!!!

 

[jiggysnitz]

I looked on wikipedia and found this about e85

http://en.wikipedia.org/wiki/E85

I dont think I would use it. But I'm by no means an expert, I'm just going off what this says. Hopefully its wrong!

 

[boostin_2_high]

Check this out....
http://www.abelracing.com/
Go to Tech Info and then E85 Testing. There are quite a few guys running around on straight E85 with no ill effects around here and with great power gains. i myself am a firm believer in this stuff and what it can do, not to mention the lower price.

 

[tkelly27]

I love E85.

BTW, running the lowest octane gas possible will give you the best gas mileage. At least that's what all the data I've heard has pointed to. The stuff they add to enhance the octane takes away from the energy per lb of fuel or something to that extent.

I run pump regular, cheapest I can find. It's not worth the extra $$ for extra boost as far as I'm concerned. If I go to the track I'll get a tank of premium, otherwise, regular.

If you want to get the most out of your car, run premium, that's why they sell it.

 

[vc_wannabe]

Higher octane burns hotter and more complete, and prevents premature detonation.

If you want to run low octane for a bit I dont think it will hurt much, you may get some a bit more carbon build up, but as long as you are not going w.o.t. you should be fine.

 

[matthewdesigns]

About the E-85 gas stations, Yes we do have it hear in wisconsin and there is a station about 30 minutes away from my house. its going for alittle over 2 bucks.

PLEASE tell me we can put e-85 in our cars.. please please please!!!

Read these:
http://www.codsm.org/forums/showthread.php?t=1328&highlight=ethanol
http://www.codsm.org/forums/showthread.php?t=460&highlight=ethanol
http://www.codsm.org/forums/showthread.php?t=1393&highlight=ethanol

then search this site for "E85" and "ethanol".

Unless you are doing a low-percentage blend with pump gas, there's more to it than just pumping it in and running. I ran a tank or two of 30% E85/70% pump 91 and got a few extra degrees of timing, but i have better luck with leaded race gas for cranking the boost. And for purely economical purposes, I don't know if it's worth it after you consider what may need to be done to keep the performance aspect of your car in tact. And isn't that why we drive these?

Our local DSM shop has 2 cars running e85 full time...you'll see the mods under the first link listed above. The screen name to look for is JackM...

 

[Eclipse98_RS]

E-85 sucks. Dont skimp on gas, if its $3+ a gallon so what? Gas is something you need, unless you want to be ultra cool and drive a bike everywhere.(NOT a motorcycle, a bike bike)
Gas is relatively cheap here $2.92 for 93 octane. Its only like $33 to fill the car, that isnt that much. I do agree that gas prices are out of hand,but they will probably be that high forever, unless another 9/11 type event happens where travel goes down like 400%. I dont really see it being that much of a hasle though. If you had an even mildly successful lemonade stand you could buy a tank of gas, let alone a full or part time job.

 

[Eclipse98_RS]

I love E85.

BTW, running the lowest octane gas possible will give you the best gas mileage. At least that's what all the data I've heard has pointed to. The stuff they add to enhance the octane takes away from the energy per lb of fuel or something to that extent.

I run pump regular, cheapest I can find. It's not worth the extra $$ for extra boost as far as I'm concerned. If I go to the track I'll get a tank of premium, otherwise, regular.

If you want to get the most out of your car, run premium, that's why they sell it.

I get the same mileage with premium as I did with regular. If a car says Premium unleaded fuel only, its usually there for a reason.

E-85 doesnt save you any money. You get less mileage out of a tank and unless you are running a big ass truck, you arent gonna see any money saved.

 

[gsx951]

E-85 sucks.

This is not correct.
There are EVOIII 16G cars making better than 450whp on E85.

 

[gsx951]

E-85 doesnt save you any money. You get less mileage out of a tank and unless you are running a big ass truck, you arent gonna see any money saved.

If you live in a state like Wisconsin, where E85 is subsidized by the state, you WILL save money.
The pricing structure is not like that of gasoline, many of the mid-western states have subsidized it to promote it's use.

 

[mattspyder]

hmmmm I cant log into that one website.
so its kind of a at your own risk thing.

 

[gsx951]

hmmmm I cant log into that one website.
so its kind of a at your own risk thing.

All of the information required is on this site but yes, anything you do is an "at your own risk thing."

 

[Locke]

The higher the octane, the more resistance to detonation.

Turbo cars are factory tuned for premium fuels, thats why it says "premium fuel only". Don't boost with low octane fuel.

Mileage does go down with e85 (as you want an afr around 8 or 9:1'ish) but the higher octane (105 or 106) allows for more boost, or a more aggressive tune.

There is a lot of info on running e85 here on tuners. Look for it.