I've had my TL since may this year and have been using premium gas from Shell.... my average on the highway was 600km... EASILY... by the time gas light hits.. and mind you... our gas lights come on prematurely.... I was always amazed at how good the mileage is for a V6 and all the weight but I ended up experimenting with it a little over a month ago to see the difference regular gas would do to it.. and my gadd was i amazed... 480km and the light was on!.... I havent used regular gas since and my average hasnt gone back since!! ....

I've gotten it down to as low as 7 L/100 km on the highway before... now it wont go down less than 10 L/100 km and roughly 480 - 500 km til the gas light turns on doing city and all highway..... what did i doooooooo!!!

 

Hey, I'm sure that one time fill up of regular gas didn't do anything. In desperate situation you may succumb to using lower octane gas...

Are you resetting your MID - trip computer? You haven't done anything else? Also this is a little factor, but weather also affects mpgs.

 

you might have gotten some bad gas. try a fuel injection cleaner. also, clean out or replace your air filter if you havent done it in the last 10k miles.

have you considered extra weight? maybe you added something to the trunk at the same time (sub, tools, dead body, etc)

have you been driving the same routes during the same time of day for your tests?

these are just some possible explanations for the change in mileage.

 

How long did you run the regular gas for? How long has it been since you changed back to premium? It could be that your ECU hasnt reconfigured since you changed back.

 

Exactly what I was going to say.

Pull the necessary fuses (can't remember which ones) and you should be back to normal.

 

The stiffs always screw up your mileage....that's awesome!

 

Fuel and fuel mileage is a common topic on Bob Is The Oil Guy (click here).

From what I learned on BISTOG, our gasoline comes in two versions. A Summer blend and a Winter blend. If I remember correctly, the Winter version will yeild less mpg. And, this is the time of year for the season to be changing and I assume the oil companies are switching to the Winter blend. I too notice a huge drop in my mpg in the past week....and you know damn well that I ain't got anything heavy in my TL.

 

I started a thread on BITOG to ask about the Winter blend. My username on BITOG is No_Traction.

http://www.bobistheoilguy.com/forums...99#Post1232999

 

Good to see some fellow BITOGers. It's not like it's hard to guess, but I'm BuickGN over there. I stay quiet usually because of the thin oil Nazis over there and any questioning of a -10W-0 starts a 20 page thread defending thin oil.

 

i actually lost weight on the TL.... i used to run 2 12's.... now im running 1 12....

i only used regular gas that one full tank... i've probably filled up 6 times since....

i'll definitely look into fuel injection cleaner and cleaning my air filter in the next couple of weeks to see if it helps...... any other suggestions???........

 

Ruined that thread....