hey, i have a '99 tl with only the intake resonator removed and one of the exhaust resonators removed. I have been getting terrible gas milage. i recently cleaned out my egr port, but it didnt make any differece. i havent been able to break 300 miles on one tank of 17 gallons. i take it easy too with only an occasional WOT. the car runs great and goes good but the gas mileage is really bad. what could be the problem? any ideas

 

First of all our cars dont get very good gas mileage. ~17-20 City Driving
Try driving on the freeway more often, unless you are getting 17 mpg on the highway, which isnt good.

Try seafoaming your car, change spark plugs, oil change and see what happens

 

Check all the obvious stuff- air filter, tire pressures, alignment, last tuneup date, excess weight from the golf clubs you carry around in the trunk, etc. Driving style is big part of the equation.

 

all i do is city driving, but i have less than a 1/4 tank left and i only at 220 miles. i have only had the car for about 2 months and bought it with 105k miles. so plugs would prob be good to do and my next oil change isnt due till 107k. i have heard good and bad things about seafoam and dont want to chance wreaking my engine by it

 

the air filter is new, nothing in trunk, all my tire pressures are good, i dont know about the alignment but it goes pretty strait if i let go of the wheels and i dont know when the last tuneup was

 

I get 18 mph primarily all city driving. Its normal, engines are too big and car weighs too much.

 

ive also been using 89 octane gas and im gonna try 93 and see if i get any better

 

Yeah, 93 should give you better mpg.

 

my car has a 15 gallon tank, and i get 20-22MPG on average using shell 93, i never beat on it, its a heavy automatic fwd sedan...i know its not fast.

btw its a 03 TL-S.

 

Well there's the problem right there. The 2nd gen TL just doesn't get great mileage in stop and go city driving. As mentioned above, it's a relatively heavy car with a V-6. Put a TL on the highway and you can see 33 MPG. Drive it around town with a lot of stop and go driving and you might only see 15 MPG.

My 1999 TL consistently manages 25-26 MPG with a 75/25 split of highway and city driving. But once I start mixing more city driving in the mix the MPG drops substantially.

The hard reality is that these cars get lousy fuel economy in city driving. Seafoam will not change that fundamental fact.

 

This will have no impact on your mpg. What you need to do is stop driving in the city to get better mpg. If you are easy on the gas and let it shift around 2K you'll get around 20mpg.

Expect 25mpg mixed and high 20's highway.

Otherwise consider getting a smaller car for city driving.

 

Everything sounds normal.
I get about 17-21 mpg mixed and with short trips (work is 3 miles or so away), so running cold and warming up kills the mpg too.

DId you replace tires recently? Having something grippy and sporty, they will do more damage to mpg than good. If they are close to bald, they will hurt your mpg.

Also, keep your pressure at about 32-34 - depending on tire brand and size. Anything more and you are ruining your tires and getting a harsh ride for a 1% increase (it wont compensate for the cost of new tires replaced prematurely). Anything less and you will be hating life at the pump too.

These cars are NOT bad cars in terms of gas mileage and the bang you get for each gallon. Go ahead and list another car in this price range (used now, of course), performance (V6, 260hp), capacity (seats 5) that does better... I haven't come across anything. You'd be hard pressed to find one.

All the numbers sound fine. Cars are a utility and all utilities cost money. You can make "investments" to help reduce these costs, but after a while you hit the bottom of the curve and you will be throwing money out the window. For me, 17-21mpg (mostly city) is the bottom of the curve.

 

I am curious about this , was this done by you , or done before you got the car ( you said you only had the car 2 months ) I am thinking if this would interfer with the proper amount of back pressure that is required by the engine to give the ' factory ' level gas mileage. But, as a member has already stated , these cars are not great on gas . When I first got mine I was shocked at the milage return and thought there was something wrong. I remember thinking to myself , ' A Jap car with bad milage , whoda thunk it .

 

This statement is in correct. The car gets 30+mpg on the highway. City is another story. Unless you get a hybrid ALL cars suffer greatly in the city. If you get a small, light 4cyl you'll get better then 20mpg in the city. But then you'd need a civic on the rsx.

 

i did the mods i have done

 

i have to differ. i can say that i get better gas mileage putting 93 in

 

I agree, with 93 i get better gas mileage.....but its probably all in my head.

 

300 to a tank all city is very good. Now did you actually fill 17 gallons into a 17.2 gallon tank or are you basing your mileage off of the low fuel light?

 

well you guys have to remember he has the 4 speed and the j32a1. that's gonna cut into some fuel economy as well.. i don't believe the j32a1 requires premium like the j32a2 (it's only 9.8:1 compression)

but on my type-s manual i get 250km to half, and roughly 500km to a tank if i take it easy (about 280 miles)..

and every time you go WOT that's gonna take a chunk outta your mileage no matter what

 

I don't drive my car hard at all, I put the gas to the floor once, and I drive 80% hwy(not interstate) and 20%cty and I get 27-29mpg in my 02 tl-s with 93octane. My car is all stock.....for now.

I was expecting worse so I'm not upset, but my civic that the TL replaced got 38mpg doing the same driving!

 

they require premium aswell.. seems like 99s get the worse gas mileage overall compared to the 00-03's

 

I was looking at a 99 when I bought my 02,I quickly made up my mind when I noticed the 99's had a 4spd instead of a 5spd trans!

 

but we got stonger trannys! as long as were all TL owners i say

 

i stand corrected.. but at that compression ratio personally i don't think it's necessary.. probably just another luxury car type thing

 

My car does terrible with 89 Changing up to 93 should definently help.

 

I've done a lot of consistent testing, using the same vehicle, same roads and my research suggests there is no different in MPG between the fuels. So the 10% premium on premium gas does not lead to better mileage. This was tested with chevron gas without ethanol. Ethanol in the gas may change your results.

But if you folks want to 'believe' you get better mileage I'd like to see your stats to suggest. You can find my reporting in a thread I made a while ago.

All this is actually moot point though. A 1-2mpg difference in the city makes little difference on your mileage as we'd be talking about an extra 17-34miles to a tank. Now 5-10mpg difference is something to work towards, but that would require either a different car or different style of driving.

I stick by my statement earlier, you're going to save more gas if you are gentler on the car.

 

I agree with you short term. But if you have two identical cars that are driven the exact same and all the conditions are the same; I think that the premium would help you get better gas mileage because when it burns it leaves less carbon in the motor which reduces power and efficiency.

I've never torn apart a motor that has been sea-foamed and looked at the internals to see how much if at all cleaner it is!

 

93 should get you better IMO not to mention it cant hurt and with gas prices at low why not?

 

i actually just deleted that post cuz it seemed pretty useless. kinda funny that you replied.
anywayyy, according to rob-2 this wouldn't actaully affeect mpg, but rather how clean my engine will be over time. idk, i'll probably stick to 89 when prices are low and go back to 87 when theyre really high

 

i get better gas milage and so does my sisters IS300, she actually tested it. i havnt done that on the TL though but it sure seems to help. and it seems im not the only one who thinks using 93 is better though on this thread. and how much is gas for you? its around 1.90 here (spring hill FL)

 

I'll let you know when I hit 200K how it's running.

 

I was just saying that if 93octane would have been used for the life of the motor instead of 89octnae, the internals would be cleaner which would theoretically make the engine more efficient; resulting in better fuel economy and performance.

 

very well put

 

You could be right, but the difference in build up would have to be considerable as in a greater then 1-2% increase in build up.

 

And if you also read in the other thread most arent lucky like rob-2 to get good mileage with it. Mine suffered with it. (on average 30 to 60 less miles to a tank) Every ones car and driving are different.

Its not a luxury car thing. Its the way Honda tuned the motor to run optimally on 91. And really how much are you saving switching with high prices. 3 bucks at most. Run whats supposed to be in it to keep the car running optimally.

 

I've gotten 29-33mpg hwy on 87 no problems.

 

1gallon 91 @ 30mpg for $2.29 = 7.6c/mile
1gallon 87 @ 30mpg for $2.00 = 6.6c/mile

Your MP$ is less on premium. 10% less. So 30mpg on 91 oc = 33mpg on 87 oc

The difference after 125,000 miles is $1250. Approximately the cost of the 105 service.

Kris' point gets a little fusy when you look at the same cars they produce for Europe.

Euro Accord regular vs. US Acura TSX Premium only
Euro S2000 mid/premium vs. US Honda S2000 premium only
Euro Legend regular vs. US Acura RL premium only

One might debate that the motors are tuned differently for their respective markets and in part this is correct. However their compressions don’t change and that would be the leading factor for predetonation of regular fuel.

Clearly if the s2000 at 11.1 and 9K red line can run midgrade (our 89) then your TL can run regular fuel. Why? Compare the UK Legend with 11.1 3.5v6 to the US RL 11.1 3.5v6. Both the same motors, same power yet only in the US market is it stated to premium.

Then if you really want to start thinking outside the box, start asking yourself why Honda branded cars here have higher compressions and don’t require premium. Then go one step further and ask yourself why Acura is only in the US/Canada. Might it have something to do with brand positioning and our obsession with status?

Just food for thought. Run what you like but dont be affraid to try regular, it wont damage a porsche so it wont damage our fancy accords.

 

same here.. must be a 99 thing

 

so does mine....wife had it for a week last month,
filling it up with 89 and when idling it was even gasping.:angryfire

 

ok, next tank im trying 93 and will hopefully get better, i dont know for sure what i got on this tank cause i put $10 in saturday night but i was at about 240 miles and over E.