The other day I was at the gas station and for some reason , the premium gas pump was not working , so I had to put 89 octane gas , I didnt notice any difference as far as performance , but the gas mileage increased about 50-60 more miles . it went form 220 per tank to 280. Is this possible ??

 

It can vary based on driving conditions.

 

lower octane rating will definitely not contribute to higher gas mileage. 280 a tank is good for you? 220 means something is wrong, i get 320-360 before my gas light comes on and still get 50miles after that easy. run some gumout complete fuel system cleaners next time you get your oil changed, make sure your gas tank is low then add the gumout and fill it up, that should help some.

 

By the way, check your tire pressure too

 

280 per tank? What kind of driving do you do? City or highway? I usually get like 380-400 on a tank of gas driving on the highway mostly.

 

It is mostly city . I usually get 350 miles per tank on the highway. I thought 220 was normal . I ve done some research and a lot of people get the same kind of mileage

 

no way man...with 100% city driving, I always get at least 20mpg - so I can go at least 300 miles before I have to think about getting gas.

 

yes i have also notice that when i use 89 i get higher miles than 91 octane gas

 

Check your plugs. I got 10-20% fuel mileage loss when my plug gap wore down from 0.044" to 0.06".

 

91 octane? i have 93 octane here

 

wow are you serious , i barely get 280 on local. driving highway i still get 300 only. is it cause mines 02

 

220 in the city is still bad, if other forum members are getting this gas mileage until the gas indicator light shines then there are some things you can do to get batter mileage.
1. fuel system cleaner(gumout complete fuel system cleaner, works best for me)
2. new spark plugs
3. increase tire pressure by about 3-4 points up to 37-38 psi tops.
4. check air filter or just get a K&N filter
5. clean your TB & IM

 

My car stills under warranty . SHould this problem be cover by the warranty >??

 

thats really weird. i did a whole port and polish on my IM and cleaned out my TB. i got brand new spark plugs, K&N filter, synthetic oil, and put in some complete fuel system cleaner by gumout and i still get a 70%city and 30%highway of 250 miles from a full tank.

but then again i have 99TL.. so im driving at a higher RPM than others because of the 4 gears, but i dont think that should effect it too much, right?

 

I get about 240 to the tank, but my driving is almost 100% city. Bought some fuel cleaner havnet used it yet. And have a clean K&N filter. How often do you have to change spark plugs on the TL? I havent ever changed mine.Is it the same to change as other cars. Because our cars dont come with spark plug wires, so it looks confusing lol.

 

I get about 240 in the city as well. About 400 even on highway. Highway dropped when I put Fuzion ZRi's on, down to about 370 or 380 or so (at about 37 psi front, 35 rear).
I have almost 69k on my 02 TLS. Changed plugs last week. The gaps were still good - maybe about .045 or .047, just a little pitting.
I also run a fuel system cleaner (STP brand) every 3k miles or so.
Also using a K&N. I also like to lead the pack from a light and would consider my driving style as "spirited."

Anyone see the episode of Mythbusters where driving with the windows down used more gas than having the windows up w/ AC on. Interesting.

 

Actually, there was a difference between the EPA stickers on the 99 to 00 models. Yeah, turning more RPM's does use more gas.

 

There are lots of past threads on this subject. We'll consider this one a