wow i must have a really heavy foot compared to the guys that do 25+mpg cause i only get like 20-24 with a aem cold air intake and an aftermarket mufller, also gas is really expensive in the bay area, 1.57-1.63 for the cheap stuff.

Also i heard that with some cars if you but in higher octane gas the ecu will increase the timing or do something automaticly so you get better performance because it can sense the gas isn't knocking as much, i'm not sure exactly how it works, but my friend says he can feel the diffrence with his civic si and he also said when he puts in a fuel booster it makes a really big diffrence, so i was wondering if anybody has noticed a diffrence with the lancer or if you would have to tune it up to get better performance with higher octane or the octane boster

thanks

 

My car is totally stock right now and I'm curious to see how the MPG is affected when I put on an intake/test pipe/exhaust.
I could prolly get about 400 miles on a tank, but by the time I hit about 375, the needle's already on E.

 

if your car is knocking on regular, there could be a serious problem. it should not knock on regular gas. we are running a 9.5:1 compression ratio. putting higher octane gas is a waste of money. what the ECU is designed to do is to try and burn higher octane gas with the same efficiency that it burns regular. this is done because if you use higher octane gas, a percentage of it will remain uncombusted. the ECU tries to compensate for this (i am assuming, correct me if i'm wrong). it will not increase performance however. it will only deflate your wallet.

gas stations eat this stuff up. that's why they call their gas "premium" and "super", people think it is a better kind of gas and pay more money needlessly. if you think you are getting better performance, it is all in your head. you buy the better stuff, drive a little harder, and think it is helping. all it is is a less combustable gas for higher compression engines to eliminate engine knocking.

 

i get the premium gas and all at 1.59 a gallon (price went down this week ot that) and i only get around 200 miles per tank, all i have is exhuast and custom catback....

 

i get regular gas, i have to fill up about once a week, and i dont know the price cuz i never look, i just use the shell card

 

http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm
^thanks to hobiekopek for finding that one on an earlier thread.

 

gas? what? I have to Fred Flinstone it. No, actually i get like 21 mpg on my toyota tercel manual trans 92 on regualar gas

 

I get about 32 mpg on average on regular unleaded. Its 1.59/gal. here in Nashville, TN.

 

Your friend's Si also runs higher compression and needs that higher grade gas so the stuff doesn't detonate in the head (as opposed to the combustion chamber). Honda VTEC powerplants love their compression. Cup is right about all the premium gas nonsense. Lower octane gas actually is able to have a higher level of combustibility since there is no need to worry about early detonation in the cars that use it since more than likely it's either a low advance motor or not running significantly high compression. Engines that require higher octane (boosted motors or high compression especially) need it so they won't ping/knock and scorch a valve.

 

thanks p. i was right about something!

 

i'm doing something wrong.. i think my car is broken.. heheheheh.,.. i have .. intake (aem cold air, test pipe, and exhaust.. 300 is all i'm getting !!!! heheahaehaehaeheah

 

In NM Gas is around 1.32(for plus) at stations. about 1.25 for regular. I use plus. I think in the manual it says 87 and above octane. Just thought I would give my .02

 

What the F>>>>> I'm gettin 17 mpg in my 03 lanevo 8 on the e-way.

 

I only get about 25/26! The gas in Mass is around 1.60 so it's costing me about $14 every 10 days or so.

 

Dang wished I lived in mass! I moved to phoenix a month ago and gas is $2.09 for the 88 octane. It's insane!!!!