henryle502

So before I bought my is250 from my dad, everytime he'd fill to a full tank he'd have a mile range of ~350+ and now when I have a full tank I'm getting about 236. Average is showing 15.4 mpgs and tank average is 12.4 mpgs. Anyone else have this issue? Gas is gas but I was just wondering. Fill with 93 btw, if that matters. I also don't 'hoon' it.

Bichon

You didn't say anything about your driving mix, and how it differs from what your dad was doing. Is it mostly city? Lots of short trips? Is it cold where you live?

I've found that the combination of many short trips and cold weather just decimates my mileage.

MikeyK02

iTrader: (7)

Theory here...carbon build up. I was at 19mpg with a highway...city mix.

Had carbon removed from valves...changed spark plugs...now at 24.5 mpg

henryle502

Yes mostly city but some highway for work. A lot of short trips as I go to school and work and repeat, also pretty cold in Ohio.

MikeyK02

iTrader: (7)

Hmm im in Ohio too. Check anything that deals with fuel management

henryle502

yeah will do, thing is with carbon build up- lexus dealer over here checked the complete motor a couple of weeks ago and everything was healthy and fine.

RussZTT

First thing is I would check the plugs. How many miles on them and when was the last time you changed them. If there is a build up on them, that will cause the plugs not to ignite fuel correctly.

MikeyK02

iTrader: (7)

How did they check it?

CML17

I have an 2006 Lexus is250 2wd I fill it up with 93 octane every week, I only get 212 miles it used to get 350, I know the o2 sensor needs to be replaced and maybe spark plugs if I were u I'd run some seafoam in ur tank when u fill it up good stuff I used it before.