I have had my 3gen TL since may of this year now. Usually when I drive on the highway I get 33 to 35, but lately i have been getting 28 to 30. WTF HOW DID THIS HAPPEN. It only has 5000 miles on it. I did an oil change with mobil 1, i only use premium, i dont use the ac nemore or less than usual. WHat the hell is going on??
Also almost all of my miles are highway miles and i almost never gun it off the line.
Ne ideas plz post them, thnx

 

ur lucky....i get like 16-20........IF IM LUCKY

 

Where do you live?

 

That's irrelevant.


He stated he had been getting 33+ driving, and now he only gets ~28-30 with the same driving style.

Have you checked your tire pressures lately? My TL started feeling sluggish lately and I checked my tire pressure and they were all 29psi. I pumped them back up to 36psi (max is 44 on my tires) and it's much better now.

That's the only thing I can think of right now.

 

Well, it kinda does. I'm sure CA, TX and FL don't get the same type of winter fuel we get in CO, or in the North East/Midwest.

Yeah, I'd check the tire pressure and try different brands of gas.

 

I live in MA and I am pretty sure our milage has taken a slight dip recently.

 

For starters, there are numerous variables that effect your gas mileage and/or its computation method. Unless you're driving in exact/same conditions your mileage is bound to vary. My guess is your 33-35 mpg figure/result was achieved in prime conditions and/or taken from the TL's MID readout.
Though possible, it's still on the high side for average mileage figures posted from numerous forum members with AT TL's. I myself drive like an old lady most of the time and will average 28-31 on the highway. I have had the MID tell me I was achieving 34mpg but when I performed my own "gallons used to miles traveled" it was closer to 32.

Overall, continue monitoring it. Your 33-35 mpg is awesome, but in all reality given the changing variables effecting ones mileage, 28-30 mpg is a very respectable outcome.

Cheers

 

You are getting the winter blend of gas and it gets poorer milage. I could always tell when they switched over in my old subaru in the fall ( lived in CT at the time). I would drop about 2 mpg

 

I wish I had your problem. I'm getting around 18 city and 22 hwy.

 

Same here. I was dissapointed.. maybe I need to start driving slower?

 

its amazing how such a fun car can cut ur gas mileage literally IN HALF....i use 93 octane....and sportshifting all the time...and my numbers are TERRIBLEEE

 

I find it hard to believe you get 22 hwy. If you're stuck in bumper to bumper on highway, it doesn't count as highway driving.

Have you never done a long highway driving with the cruise set @ 60+?

 

All highway driving is not equal. Some of us have busy highways and speeds might run 35-75 mph depending but its still highway driving.

 

Some cars, like my Mazda Protege, are commonly plagued by things like the poor design of the rear brake calipers, whereby the sliders, unless overserviced twice a year, tend to let the pads drag on the rotors, causing premature wear, and likely making the car slower, use more fuel, and possibly dangerous. Is this a TL problem? Try jacking up a couple of corners, like when you're rotating or changing your tires, and try to spin a wheel by hand to see if it goes around only once, or three or four times. Is parking brake adjustment a possibility? Dirty air filter?

 

It's not at ALL irrelevant! It's a major factor in mpg. In most areas, it's getting quite a bit colder lately. That means it takes the car quite a bit longer to warm up after a cold start. Cars get bad mileage during that warm up period. Mileage, overall, can easily go down 10% due to colder weather. There's also the tire pressure and fuel issues others have mentioned. Also, even having lights on makes some difference, and lights are used more in the winter. A/C is used less or not at all, but I have found that the colder weather is worse on mpg than using A/C in the summer.

I have noticed that cars even get less mpg on the highway at the same speed in winter, by a little bit, even if tire pressure and gas are equivalent. Maybe it's higher rolling resistance (colder wheel bearings, tire compound and other factors?), or even the colder air in the intake (although some say that's supposed to improve things).

 

You're getting there. The primary reason that modern engines get lower fuel economy in the colder months than in the warmer months is.. air temperature.

Colder air is more dense. It contains a higher amount of oxygen molecules per cubic foot than does warmer air. Now what this means to your engine is this.

Your ECU wants to maintain the air/fuel ratio at, or as close to 15:1 as possible (actually 14.7: is just about ideal). When the various sensors, particularly the oxygen sensor report a higher amount of oxygen in the air, what they are reporting is higher exhaust temperatures. So the ECU will deliver a little more fuel to the cylinders per intake stroke to offset the slightly leaner mixture. Your engine will produce more power and have noticably better throttle response when this takes place, but will burn more fuel per mile. The reverse of this occurs in the warmer months.

It's a trade off. More power but lower fuel econiomy. In the summer months, I regularly get 26-27 MPG in my daily commute to work and back (suburbs which includes business and residential travel in the commute). In the colder months, my mileage drops off nearly 2 MPG. Incidently, I have an '04 6MT TL.

The best mileage I've ever managed with my TL was just this past September on the first leg of my vacation trip. With no special gas-saving techniques, moderately heavy Sunday interstate traffic, 86 degrees outside, car packed with two people on board, an the A/C running the entire time, I managed to get 33.94 MPG. And that is NOT from the MID.. it is a calculated figure.

 

For last two weeks I got 12 mpg in the city (New York)
I drive SS always...
Once I am on hwy I get 30+ mpg

 

I'm averaging 21 right now, I tend to get really bad gas mileage the first year I own a car. Gotta make sure I blow all the carbon out

 

And don't forget, tires act differently in colder temperatures..

I'm sure that has to affect rolling resistance.

 

When you changed the oil, did you use 5w20?

If you use a heavier wt gas mileage will suffer.

 

Could it be the O2 sensor?
Leaner mixture before, richer mixture now?

 

Now since i'm only ~5 miles from u, we should be using the same NJ gas mixture. with all that crappy RT10 traffic in the morning, i get average ~24+. maybe you got lucky and got the 300HP version due to production line inconsistency ;-). i had to bring that up again.

 

im just a very aggressive driver.....but im still disappointed that i get 15MPG

 

wow lots of info, thats interesting, i didnt know colder weather would affect gas mileage. Although a cold (not super cold) engine is better for racing isnt it?

 

Please explain how having your lights on will make a difference on gas mileage. I'm very curious.

 

It is an electrical component and it draws current which requires some work by the alternator. This puts a load on the engine thus reducing gas mileage. It should be quite small though.

 

Cold engine? no

Cool air helps for racing. You dont want to be out racing when its 120 degrees outside.

The key is to get cold air from the outside (cold air intake) since its dense and will produce more power. Hot air from inside the engine bay reduces performance.

 

No it's not. If you had said "parts of the engine", you would have been closer to fact.

The idea situation would be to have the cylinder walls, pistons, valve faces, and combustion chamber to be at normal operating temperatures while the intake manifold, plenum chamber, throttle body, and any other components of the intake system to be cool.

 

You might have given the impression that higher electrical loads on the alternator translate to a greater engine power loss due to having more resistance to being turned. This is not the case. An alternator does not increase it's resistance and require more engine power as electrical demands increase.

What happens is a little less electical energy is available for the coils and spark plugs.

 

I am sure the door gives you the correct tire pressure for the car, not your tires. It's been a while but I doubt the pressure recommended by Acura is 36 PSI. Good luck if you hit wet or snow covered roads carrying that kind of pressure in your tires.

 

Yeah all sorts of snow covered roads in Georgia.

The recommended pressure is for the factory tires which my car no longer has, at least that's what I've taken it to mean

 

They started blending gas with more ethanol and cheaper stuff to keep prices down after the prices shot up.

Just one thought.

Weather, atmospheric pressure, humidity, and the transmission "auto-adjusting itself to your driving style" all play a part too...

 

Certainly you know more than the manufacurer of the car you choose to buy. If you are happy with 36 pounds of air in your tires then by all means go for it. Seems I remember a song, even though it dates me, "It's a Rainy Night in Georgia". I am by no means an engineer, but the expert that I trust always says ignore what's on the tire and trust what's on the door. The gentleman is Pat Goss who you may be familiar with from Motor Week.

 

I've kept the TLs tires like this, my Accords tires like this (all the way back to 1993) - never maxxed out by the tire's info. I've never had a traction problem. The ride is a little stiffer, but the steering feels better and the gas mileage is a little better.

 

For the record, an alternator pulls powers off the engine proportional to the electrical current load (with the exception of some belt friction), unless the engine is turning too slow to support the draw (in which case the battery contributes as well).

I have not noticed a decrease in fuel mileage in cold weather this year since going to a homemade cold/ram air system in the TL. The same thing happened when I converted my '99 Civic Si to cold air intake. Apparently the denser air outweighes any fuel atomization issues at lower temperatures. With the price of fuel these days, it will not take long to pay off the materials I used to fab the intake.

 

Having your lights on will drain the battery and eventually cause the alternator to kick in creating drag on the accessory belt and thus reduce your gas mileage.

 

Hi Sarushibai,
Your difference in gas mileage could be due to many factors, one in particular is the change of weather. That's of course, assuming your style of driving is still the same. Mobil 1 oil would not make your gas mileage decrease if that's what you're wondering...

 

On cars that preceeded electronic idle control (and that didn't have devices like solenoids pulling on the throttle to compensate), turning on the headlights caused the idle speed to drop. Turning on something else like the climate control fan caused it to drop more. I've always attributed that to more demand for power by the alternator. Is there another explanation?

Also, It seems like if there isn't any additional resistance by adding more electrical demand, this would be a source of FREE energy! Have the alternator charge batteries that feed a electric-driven supercharger, and it would mean free power.

 

Very true Hybrid.

An alternator will continue to draw more power/place a greater load on the engine until its output equals the max amperage it's capable of producing.

Thus, if it's a 100amp alternator, the resistance from the alternator will increase until the "load/draw" from the battery equals or exceeds 100amps.

Cheers

 

I find it very unusual that some owners experience an average of 25 mpg and others experience 20 mpg....


I really believe putting super will help. When i first got my car I'm pretty sure the dealer put regular in. I can feel the difference in acceleration on a car using regular. Anyone else feel the same way?