whack7

Hi,
I own a 2000 3.2TL with 128,000 miles. I had the timing belt replaced about 15,000 miles ago. Before the belt replacement, I averaged 25-26.5 mpg fuel economy. Since the replacement, I now average 21.5-22.5 mpg. I have had my mechanic recheck everything to make sure the timing is set correctly. It was tuned up just before I had the belt replacement. I have since taken it to the Acura dealership to get their opinion and they told me that 21.5-22.5 was not out of the ordinary for that vehicle and that replacing a timing belt should have no impact on fuel economy. My opinion: It is extremely out of the ordinary when I was getting 4-5 mpg better before the maintenance. Does anyone have any suggestions, thoughts, or ideas that might help me bring my gas mileage back up to where it was? I am willing to try almost anything at this point...
Thanks!
Talley

fsttyms1

Unless they timing was off there is nothing that the belt would do to cause that.. What did your tune up consist of?

whack7

Tune up included oil/filter change, air filter, new Acura/Honda spark plugs, a can of MOA additive with the oil, and maybe a fuel additive.

fsttyms1

Huum. Change fuels? ethanol reduces mileage. Any change in driving? Honda checked the timing and every thing is where its supposed to be?

whack7

Timing was double checked by my mechanic (not a Honda employee.) He's been doing this kind of work for 25 years though. I get no change in mpg whether I use 93 octane or 87 octane. Driving habits have not changed...40 mile commute to work and 40 miles back home. Yep, that sux!

Southern

If the timing belt was off by even 1 tooth it would run like crap. I would double check the gap on your new spark plugs.

fsttyms1

Actually no it wouldnt. Ive had mine off by one and it ran fine

sbuswell

give it time and I bet the problem solves itself. just keep close eye on your mileage the next 3 tankfuls and I bet your MPG gets higher each fillup. you did a fair amount of maintenance on your car and the ECU is compensating for the changes and may be running a bit rich right now.

SoCalwarrior

check your airfilter and for a vacuum leak. it might be time to change the O2 sensor. just some suggestions. good luck

I just recently changed my timing belt and water pump. by myself too, not bragging though. Fuel ecomony hasn't gone down for me.

1999 TL with 108,784 at time of change.

whack7

Cool, thanks for the suggestions!

SoCalwarrior

have any luck?

fsttyms1

An airfilter vacum leak??? no such thing. And if the o2 were going bad it would give you a cel.

acurabum

A can of MOA additive with the oil that will make your engine oil thicker = consume for fuel...
I would not sugest any additive to the oil ....Do you feel like the car does not pick up as
good as before maintenance ?

BigLizard

I got my timing belt replaced recently as well and everything is fine. What kind of gas are you using?

whack7

I'm currently using 87 octane, but have used low, mid, and high grade with little or no change in mpg...or performance for that matter. I'm not really sure how to check for a vacuum leak. The air filter is fine. FWIW, my last 5 tanks have been as follows: 21.5, 21.5, 24, 23, 23 mpg respectively...a little better the last 3 I suppose, but still not the 25-26 I was getting before. The 24mpg tank was about 50% interstate driving, so it should have been higher. Recapping, before maintenance: 25-26 city, 28-29 highway....now: 21.5-23 city, 25-26 highway.

Thanks!

joseph_99tl

might it be a worn idler pulley?.

Luke7

I had my plugs replaced at the Honda garage once and one was weak / misfiring occationally. They replace the bad plug and everything was fine after that. Timing belt should have no effect on mileage if properly installed. I'd say plugs made the difference.

fsttyms1

Well for starters I would stick with 91. I saw a drop in mileage going from 93 to 87. Switching back and forth isnt recomended. MIxed driving those #s are average, and im having a hard time believing you were getting 25-26 in the city before and only 3mpg more on the hwy.

fsttyms1

mrodriques

My bet would be on your octane level. Go back up to 93 octane. Write off your first tank, and check mileage with your second.

Bob_F

That's good advice. I would even give it serveral more tanks to average out the normal tank to tank variations.

Bob

fsttyms1

exactly, plus every tank is usually or can be different from the next so one isnt a good indicator. (and i still findit hard to believe the 25-26 in the city mileage)

TLuvr

I'd be more concerned about your fuel injectors. There are warnings in your owner's manual against using fuel additives (for cleanng injectors). All Honda/Acura stste this. Hopefully you did not damage anything but I would have it checked out. What fuel additive did you use?

laidback93

I'd be happy to get that on the freeway!

acurabum

My TL-p02 get the most 21 mpg in city and 28 mpg on highway ....
I have a hard time to believe you could get 25-26 mpg in city too .....

whack7

Ok guys,
I've gotten several "I don't believe you's" on my mpg claim of 25-26. When I say city, I am referring to my 38 mile commute into work. The first 7 miles is highway going speed limit, the next 25 is sitting in stop and go on the highway (which I consider equivalent to city driving), and the last 6 is highway going speed limit. Then sometimes I drive to lunch in the city too. I have no reason to simply lie about the mileage I was getting. I think one comment said that I should get more than 3 mpg better on highway than in city...I have gotten up to 30mpg on an all highway roadtrip before...I promise.

fsttyms1

^ well any thing with bot would be a mixed driving and not pure city. Those 12 miles of hwy really help to contribute to the overall calculation. I believe the hwy mpg cause a get that and better all the time. On typical all hwy i get in the low 30s quite a bit