Tips to improve gas mileage
 

Do ive been on this website and noticed people talking about getting 300+ miles out of a 2003 acura tls and i have a 2003 acura base model and only get about 210 miles to a FULL tank and ive always thought it wasnt the best but any tips to help change that or is it normal? Ty for your time

210 miles on a tank? What kind of driving? I am in horrible stop and go daily and I always get over 300 before the light comes on. Have you been able to do a full tank of only highway/freeway driving? I usually get around 400 on a tank if I'm doing a road trip. Mileage has for the most part been pretty consistent in the 12 years I've had the car.

How long have you had the car, and what is the maintenance history?

I agree with @SuperGreg, both my J-30 equipped Accord and my J-32 equipped TL easily get 300+ miles on a tank for mixed daily driver mode driving, and will get into the high 400 mile range on a road trip. Said another way, something ain't kosher with your car, errrr, unless you're sitting in traffic all of the time.

Miles per tank isn't always the most accurate. I'd fill up then drive until you're at 1/4 tank or so, then refill it and divide the miles by the gallons. Also note what % is city vs highway driving. I doubt you'll get much more than 22 or so in town, 28 or so on the highway. If it's significantly less than that then I'd be concerned. It seems the 2G, 3G and 4G all get around the same mileage. I get about 25MPG with around 60/40 City/Highway driving. I got closer to 28MPG in my 3G but it was a 6MT and I did more highway driving with it than my 4G and it didn't have an AT leaching power.

As far as mechanical stuff goes, try cleaning the MAF or MAP sensor (not sure which the 2G uses), run a can of Gumout Multi-System Tune-Up and make sure your spark plugs and O2 fuel/air ratio sensors are working well. Spark plugs aren't too expensive to replace but the O2 sensors can be. And it's difficult to tell if they're getting old and less accurate.

I'd start with measuring mileage more accurately then seeing where you sit after that.

I started adding to my previous post and then got called away from my desk. Here is the basic content of what I had been writing:

• As for what you can do to improve things; assuming you are having no codes or other driveability issues, it is well known O2 sensors have a tendency to get lazy; not lazy enough to throw a code, but definitely enough to cause fuel economy to suffer.
• The above said, while I am not an advocate of throwing parts at a problem, in cases like this, I typically recommend the first thing folks do is to replace the upstream O2 sensor(s) (I believe your car has just one upstream sensor). If you opt to go this route, use an OEM Honda or a Denso O2 sensor, Bosch sensors are well known to cause more issues than they solve.

So to be more clear, when I say I get xxx miles per tank I generally measure that when the gas light comes on.

OP, how is the car's power? Does it seem normal or sluggish?

Another user had a frozen caliper pin that was causing drag and killing their mpg.

I would get an OBDII scan tool and install Torque on your phone, and check your fuel trims and O2 sensor readings to see if they look normal.

The problem with this advice is I cannot tell you how many times folks have done that, gotten "normal" readings, and yet the issue was still the upstream O2 sensor.

Agreed! 210 miles per tank, equates to approx. 12.4 MPG. It's either an operational issue, or there is something dramatically wrong with OP's car. To confirm horseshoe's theory, 4 years ago, 196K my 03 TLS best highway MPG = 29. After TB/WP/Plugs/, etc. no real increase in highway MPG. Installed, up-stream 02 Sensor, highway only MPG, increased to 34-36 MPG, with extremely conservative driving. If OP's actual MPG is correct, 12.4 MPG, with no mechanical issues, and modestly conservative driving habits, THERE MUST BE A HOLE IN HIS FUEL TANK!

If the O2 sensor is bad enough to be causing issues I don't see how you could have normal fuel trims. Maybe they were not checking long term trims?

Cannot tell you; what I can tell you is lots of experienced folks who had the same notion as you have come away scratching their heads when the replacement of the upstream O2 sensor dramatically improved fuel economy.

Ive had this acura for about >1 year and the maintenance record is non existent i bought the car from a 23yr old with 4 kids and it was HORRIBLE only for aout 1.3 k i had to straighten the subframe from a previous crash and that stopped eating my tires as soon as i got it i did a fluid change on almost everything although i should mention my gas milage was noticeably worse before i "changed" the spark plugs and cleaned out the gunky a** intake manifold there is also a kind of clinking in low rpms or idle maybe valves??????idk but if anyone can make sense of any of this thank you very much! I plan to get this car running O.K. and find myself a clean title tls of the same year

Difficult to imagine, " i should mention my gas milage was noticeably worse before i "changed" the spark plugs and cleaned out the gunky a** intake manifold " MPG "noticeably" worse, than 12.5. Did you follow the FORUM recommended procedure, for cleaning the air intake system? Did you notice, which specific plugs, you removed from the engine. Which specific plugs, did you install? Re: " kind of clinking in low rpms or idle maybe valves?????? ", would it be possible, to post a video, of this "clicking". How many miles, on your car?

Based upon this description, it sounds like the previous owner used a K&N type of oiled filter, a filter type which is absolute crap for street applications and they don't filter worth a damn. Now you've remediated the effects of the modified intake, and are still experiencing poor fuel economy, the two most likely places I'd look are the previously discussed O2 sensor, and (I believe also already discussed) brake calipers. After a drive of a few miles down the highway, stop and wave your hands around the wheels, if one or more are REALLY warm, you have dragging calipers.

Thanks so far!
Adding to my list of unknowns i removed A (1) muffler The other day out of boredom and had to run to the store and it smelled like sulphur? Like it was a nasty smell when i accelerated. Also previous owner had oem intake BUT was cracked and the air filter was upside down😵.

TBH i just grabbed extra spark plugs in my shed and screwed them in they looked similar and im PRETTY sure i didnt strip the thread also i will try to get a vid on this thread tomorrow and my car has 163 k miles

A very dangerous thing to do, just because plugs "look similar" does not in any way mean they are mechanically compatible or any where near the correct heat range for your engine. My recommendation is to yank those plugs and put in the factory recommended plugs.

Thanks!👌 ill do that asap

A good tip on how to improve mileage in these cars is when it comes time to replace the tires, look for ones that are rated low rolling resistance like Pirelli P7 Cinturatos or Michelin MXM4's. I noticed a small bump in highway mileage when I had my old Pirelli P7's on my TL. On my best run I was able to crack 800km on a single tank (used almost 60 Litres of gas tank holds 65ish) with a fresh K&N panel filter when I used to do over 90% highway driving for work. I wanted to see what the best mileage I could get out of one take and 809 was my best but with the change in my commute I'm barely able to hit 600km if I'm lucky since I'm doing mostly city now and with the leaking fuel tank it's even worse because fuel is evaporating away while the car is sitting :S
Also make sure the EGR and Intake passages are clean, it really helps if it's never been done.
Free up the car's breathing, keep the maintenance up to date with OEM fluids and parts and try to reduce friction, drag, and weight wherever you can and these cars can surprise you with the mpg.

FWIW: Out of curiosity, I completed a FULL to Empty, MPG test on my 03, 240K TLS, yesterday. 65% Hwy, 35% in town. 425.3 miles, 16.139 gallons to fill, = 26.35 average, MPG. Due to extremely (WET) weather, recently, approximately 30% of this test, was performed, during rainy weather, with headlights, and w/s wipers. ON.

Hey frankjnjr, you mentioned the forum-suggested method of cleaning the air intake - got any more info on that so I can find it in a search? I'll be cleaning my IACV soon so I figure I might as well try to get everything else while I'm there.

A partial induction system service, was posted some time ago, in the DIY section, by fattysystems: Originally Posted by fsttyms1
http://www.acurainspired.com/gallery...=1914&uuid=290

start off by getting 3 or so cans of SPRAY carb cleaner and acouple small scrub brushes.
if your engine is any thing like the 2nd gen
baisicly you take the plastic engine cover off 4 10-mm bolts. then disconect the battery. they disconect the rubber hose that goes from the air box to the throttle body. continue to unplg any thing that goes to the intake (any plugins hoses) then there are 10 10mm bolts on the top plate (the part that sticks up thru the plastic engine cover) oull that straight up being carefull to not damage teh gasket. then there are like 8 bolts (12mm i think, i cant remember off the top of my head) then you are able to pull the upper part of the intake manifold off (double check before you pull straight up that every thing is disconected) then get your self a nice place to work and start cleaning. (stick a bag over the TB before you hose every thing down like in my pic to be safe)
it sounds like alot but its really easy should take about a hr to do " ******** I can't seem to find the thorough Induction System cleaning, i mentioned. There are several, in depth videos, on Youtube, regarding the complete (Cleaning) process. Perhaps, these are the ones I recall. It's been four years, since I did mine. Hope this helps.

Mpg
 

I have a 2003 cl type s, 6 speed and want better gas mileage, these vehicles have a 17 gallon tank and should get 29 mpg hwy, so should get just under 500 mpg on hwy , of course we do the spark plugs , tires psi, air filter , pcv , etc but still not what it should be , thanks for all info

Where does that 29 mpg number come from?

FWIW #1, just because a tank is 17 gallons does not mean there are seventeen USEABLE gallons in the tank.
FWIW #2, I don't know if the CL Type-S is capable of returning the same fuel economy as a 3G TL 6MT, but last fall under nearly ideal conditions I went something like 534 miles on less than 16 gallons in my TL; the mpg number was something over 35.