So i have found out how bad speedway gas is around my house. I got only 17.8 mpg after my intake mod and K&N filter, but before the filter i used shell gas and got 20.3mpg with the same driving i always do, alot city, some highway, but heavy traffic so it might as well be city. Anybody know of midgrade will do better mileage in my 02 RT? is it worth the extra 10 cents a gallon?

 

I've often wondered this myself. As I understand it Octane rating is more or less there to tell you at what compression ratio the gas will detonate at. I.E. in a Turbo engine the compression ratio is higher so you need higher Octane gas so it doesnt "detonate" I dont know if have higher octane gas will make your mileage improve.

 

Believe it or not mid grade octane will do no good. If your engine was designed to run on 87 octane that is all you need. More air equals more fuel to equal out the ratio.

 

The vehicle manual states that you can use 87 just fine if your not concerned with getting the "optimal" performance out of the car (for R/T's). 91 octane is recommended to get the full performance benefits. Myself, I tend to use Chevron everytime. There is a list of gasoline companies that participate in non-partial testing of their fuels and are considered the cleanest burning fuels in the country. Chevron is on that list.

 

i dont have chevron around here... the only stations i have are speedway, sunoco, shell, bp and mobile

 

BP is also on the list.

 

i'll have to try bp next... thanks

 

There's a little myth regarding gas companies. Most gas companies actually are using a large amount of the same gas....just different companies.

BP and Shell are 2 companies that are typically nationwide....these companies use their own fuel. Speedway, Marathon, alot of the local mom & pops, Village Pantry, and so forth....typically all use Marathon gas.....

Not to mention alot of its mixed up in the piping it up from the South.

Two things I will tell you should help with your gas.

1.) About every 4-5 fillups I will drop a can of Fuel Injector cleaner/Gas treatment into my tank. Usually costs about $8. I run it thru just to help keep everything on the cleaner side. They dont make an improvement for performance, but I've found that it helps keep things nice and clean.

2.) Check your plugs, filters, fluid levels, and your fuel pump. Your looking at gas as your only problem....but you could very well have a bad filter....a dirty line or dirty plugs....

1 other note......where I live....Shell and a couple other gas stations are kinda notorious at having water/other crap in their tanks....you may want to look into that as a possible cause too

 

i get gas at sams club, and i only use high test...i will only put speedway gas in the ramcharger, but sams club as almost always cheaper, so i tend to go there all the time now. another thing, places with higher activity will tend to have cleaner tanks, and they are less likely to have water in the tanks..but all tanks, no matter where you go, will have some crap in the gas..its just how it is.

and before anyone argues with me, my dad owned a gas station for some 30 years, and i was pumping gas when i was 10 years old...so i know a thing or two about how pumps/tanks are dealt with. unless a station is BRAND new...they have some crap in their gas...

17.8 is bad...around here, which is CONSTANT stop and go, i get over 20 with an automatic. on the highway, i have gotten as high as 28, and i drive like a maniac.

 

Yeah, I get about 23-24mpg stop and go...and about 30-31mpg highway in my 5spd...