New timing belt=better mph??

[ISHOU]

Recently replaced timing belt and tensioner in my ATX. I keep track of my gas mileage and have always gotten a consistent 22 mpg with a 60% highway 40% town driving. Last two tanks since belt replacement I'm getting 27mpg with exact same driving mix of 60/40. Not complaining by any means, just curious why the big jump? I've even been a little more lead footed lately too since the car is running great.

 

[kevinspann]

Old stretched belt = timing off? I guess. I don't think the belt would really stretch that much. Did you do anything else to the car?

Either that, or the timing was off at the crank before, and now it's right.

 

[sperold]

Any chance it was out a tooth somewhere before? That would make the difference you are talking about.

 

[kevinspann]

Edit: Double post.

I'd be willing to bet the timing was off though.

 

[sperold]

I think it is mpg, not mph you are talking about.

 

[ISHOU]

I think it is mpg, not mph you are talking about.

You guys knew what I meant. I doubt it was timing because I've owned the car 11 years and always got around 22-23 mpg.The first timing belt replaced at 100,000 was the factory belt. The second belt replaced at 140,000 to fix a case of crank cancer and always got the same 22 mpg. The most recent belt change to fix the tensioner was 170,000. Hard to believe the timing has been wrong all that time.

 

[kevinspann]

How long has that tensioner been bad?

 

[ISHOU]

How long has that tensioner been bad?

I heard it slapping the timing cover a few weeks before I replaced it but I'm certain there was some slop well before then, just not enough to hit cover.

 

[Bob Gervais]

Crank cancer ftl.

 

[sperold]

Maybe the alignment lines on the belt are finally in the right place. Or, you are out a tooth now, and it happened to make everything right.
Don't fight it.