well my exhaust has been stinking on 87 and before you ask spark plugs are less than a year old and no emissions lights and seafoam in the tank temporarily solves it. The moment i started it on 89 minimal to no smell, engine smooth as glass, and the car is super quiet again at idle. Does gas just suck in MA and old 87=89 now? or does it signify a timing issue? no codes being thrown. and the car runs fine on 87 it has just been stinky. I'm going to watch my MPGS closely I've been averaging only 17.5-18.7 around town (driving with a relatively lead foot)

 

Wow, I should consider myself lucky. My Trans is slipping a little and yet I'm averaging 22 mpgc on regular 87 octane

 

my tranny doesnt slip anymore i could do 22 at home easy if i drove it easy but in lowell city traffic kills mpgs and me and my friend have been fooling around with our cars hes got a 2003 passat 1.8t it wont spin its tires with traction control off and i made his car look downright gutless. hes been running it on 87 when it recomends 91 though...

 

I just run 93 octane in the Monte, as that's what's recommended for the LS4. However, I have run 87 octane in it in the past with no obvious issues or change in fuel mileage.

I have been switching it up between both 87 octane and 93 octane on my Cruze to see if there's any difference. To date, my best mpg on 93 octane is 35.6 and on 87 octane is 35.0, so overall I have yet to see any significant difference.

 

my friends passat is avging 13.6 according to the computer... i told him to fill it up with the required 91 and seafoam asap

 

my MPG might be bad because my FRAM air filter has 20k on it but last time i checked it looked clean but i did shake stuff out of the crevices

 

I've put 93 in mine a couple of times. But that was for knocking issues I had. Now it's Reg Unleaded all the time. Disentangle Really matter what grade you put in if your Trans is slipping right?
Once I get it taken care of, income tax time, I will Germy first real mileage reading since I got the car!

 

Think this is due for a change and should i just get another fram?

 

Wow that makes me happy, I get the same gas mileage as your 3100 lol

Different octane doesn't make a difference as far as mileage goes, but if your engine is detonating then it will help and make it detonate less

 

I've always been disappointed in the mpg of the 3100. I usually get 20-25 mpg mostly highway. If I'm gonna get mileage like that, I should at least be boosted, or V8