Hey guys, I've been gettin pretty sh1tty MPG. I haven't been drivin hard, just had a tune up, used some TECHrome, the whole deal. I can't exactly figure out why my MPG sucks arse. I realized I've been using some sh!tty gas since the price for gas skyrocketed. Does the octane and brand of a gas affect MPG a lot, or even at all? And if not does anyone have any ideas why my MPG sucks??

 

Is your air filer, fuel filter, and plugs in good shape?

 

I know everyone says that high octane is a waste on these cars.. that Hyundai tuned them to run on 87 octane.. yadda yadda yadda.... all I have to say.. all the othe cars I have had.. once I jacked the compression up to around 10 to 1 (usually 9.8 to 1) I have to run 93 octane or they ping and run on.. I know that Hyundai puts an adaptive ignition and fuel injection system in these cars to allow them to run low octane fuel.. it will pull back the timing until detonation (or pinking in UK terms) goes away... but it is my opinion that running high octane gas will allow the car to run at full advance on the timing,, making the car more efficent and powerful...

All I can say... 97,000 miles and I ALWAYS Get over 30mpg..no matter how hard I drive. I know, I check it ever tankful.. I ALWAYS run 93 octane, keep the filters, oil, and plugs clean... I do need some new wires though.

 

Higher octane fuel will burn cleaner also. This means that your pistons, head, plugs, ect... don't get the carbon build up the you get with low octane fuel. I always run my tib on 98 octane fuel, which is the premium grade fuel in OZ (regular is around 91).

 

damn i wish i could run 98 all i put in is 91 or 89

 

I run 94 octane all the time and get 35 MPG even with the mods and my lead foot. I would never run anything below the 93 in a car I own. But thats just me. Hell, I am paying 2.20 per gal for the 94 and wouldn't ever think about running the lower (89 or 97 whatever low grade is) for about 1.90

 

I use 87 octane and my car runs fine, but I do get crappy mileage. Around 23 in the city, and 30 on the highway. I'll have to try using the 93 stuff. If I can get 3mpg more, that would make it worth the extra cost.

 

Damn I wish I could get higher octane around here! The best we have here is 91 octane. 02.gif

 

I use the highest that Chevron offers.

 

aluminum engines should run higher grade fuel. (ie)civic SIR(canada&japan), bmw, etc.)
i run 90 octane lot better then 87.

yes the car manuels say you can run 87, but thats just like buying regular engine oil, rather than mobile 1 synthetic.big difference.

whatever you run you should always keep it the same, b/c your ecu adjusts to that fuel type = better performance.i've heard that changine what type of fuel you use isnt good(ie) 87 to 98 octane,but only ever second week,= not good)