i get the light at about 215-220, the tankk is good for another 35-40 miles after that, but i start to worry when i get to 25miles after the light.


oh yeah mods: i have RRM SRI and Axelback. i want teh ECU but i dont want to pay $2.10 per gallon for 91octane.

 

I drive like a granny, my insurance is almost 400 a month so i cant afford any tickets.

 

I get anywhere from 245-260 depending on how I drive of course. Thats mixed city/highway.

 

i get around 220-230 on about 8.5 gallons.... so around 26 to 27 mpg

 

23/mile before the piggyback 21 after. Ive said it before and I will say it again and again, the extra two dollars per fill up (.20/gallon for 91-93*10 gallons) is well worth all of the extra performance i get out of it. I also have RRM's sri installed.

 

For me, 10.5 gallons, give or take a fraction, goes between 260 and 280 miles. Stock setup. just remember the road isn't a race track and you don't have to race every car you line up next to at a redlight, we all know you'll beat that rusty cavalier or that old jetta... It really makes a difference!

 

Why are you running premium? I wonder if your milage would go up if you switch to regular...you'd save some money even if it didn't, though!

 

I use the mid-grade gas, 89 octane. I usually get 27-28mpg, but a couple fill-ups ago, I kept it under 75 on the freeway, and got 30.5mpg.

Stock engine, Mobil1 5w30 synthetic oil.

 

i usually set my cruise at around the same spot too

 

no matter what kind of gas i have put in my car it ends up being 200-220 miles on 10 gallons...plus i heard that the Shell V-Power stuff is awesome for a car...

 

Yes, Shell marketing does say that I'm sure it's fine gas, but it's also premium, and our cars are designed for regular. Just as you shouldn't put regular in a car designed for premium, my understanding is that you also shouldn't put premium in a car designed for regular. There was a thread on that a while back...

 

I don't see why not, other than the cost. You don't get any benefit from it, but it shouldn't hurt.

 

im pretty sure i remember someone saying that using a higher octane than reccomended causes your valves to 'gum up' somehow... i may be wrong... im sure there is someone one here that is more educated on this matter than me lol

 

Here's the thread about using high octane gas in cars not designed for it (specifically our Ralliarts):

https://www.evolutionm.net/forums/sh...ad.php?t=71542

From reading that thread I'd say at best premium is just a waste of money for us, and at worst it's actually worse for the car. As mentioned in the thread, that doesn't apply to some modded cars.

 

Inconclusive. In fact, I'd lean more towards the side that says the car may benefit from it, if he's got the datalogs and dyno tests to back it up.

Cars have been advancing/retarding timing based on octane for years. If they went to all the trouble to program in variable valve timing, why would they skip that?

Before this thread turns into another opinion war, let me say that nobody on this board knows for sure. Especially not me. I DO plan on buying a factory service manual when they come out, and clearing up a few unresolved issues.