wangjt

Hello,

I have a '13 TL, SH-AWD Advance Package. I purchased it used last Dec. They didn't say but I think it previously was a leased car. It had less than 25k miles on it when I purchased it so it's in pretty good condition (at least it seems like it was). I test drove it and everything seemed fine at the time (no weird vibrations, no jerky shifts between 2nd and 3rd, etc) but after taking it home for the past 6 months, I find that the MPG on this car is extremely low. This car is rated at 18 city/26 hwy (21 combined). I am not even close to those numbers.

In trying to figure out this car's MPG, I've purposely refrained from driving it aggressively. No hard accelerations and I basically try to be as light footed as I can while staying within the flow of traffic. For the past week, I've only been driving locally running small errands. My car right now reads 11 MPG after around 75 miles of local driving. I have only ever fill it up with premium gas and my car recently had its 30k service so everything should be working properly.

Now on highways, I can get close to 26mpg... if I coast and only step on the gas enough to maintain speed. But that is not realistic as you can't always safely maintain a constant speed with other cars on the road. If I drive normally, I get closer to 20~21 mpg.

Combined city/highway, I'm at 16-17ish driving like a grandma. What really bugs me is... I have a 2012 MDX SH-AWD which I just drive normally. I don't "baby" the gas pedal on the MDX like I do with the TL and I'm getting slightly higher MPG on my 2012 MDX (18 combined). The engines in the two cars are practically the same but the MDX weighs more and gets better mileage?

Is this expected or is there something wrong with my car that's causing low MPG?

justnspace

iTrader: (1)

02 sensors can get lazy over time

thoiboi

how are your tire pressures/ tire quality. What type of tires? There are tons of variables that lend to MPG calculation. A/C?

horseshoez

iTrader: (2)

First place I'd look is the upstream O2 sensor.

Cygnus_X1

It sounds just like my TL (2013 FWD Advance). Same driving habits as yours and my last tank averaged about 14mpg doing mostly short trips around town.
Highway numbers are usually much better, sometimes close to 30mpg if the road is straight.
I rarely average above 20mpg for a tank though. It sucks, but I can afford it so I don't worry about it.

wangjt

Tires are stock. They are all properly inflated and it was checked during the 30k service whihc I just did last month. I have the A/C on whenever I need it and I manually turn it off when I don't because I read in another thread that the compressor for some reason is always on if the AC is on... but I haven't noticed a significant difference in MPG by using the A/C. Running the A/C shouldn't be costing me 5 miles per gallon.

Is being "lazy" different from a faulty oxygen sensor? I always thought the check engine light would come on if it was the oxygen sensor. I'll get it checked out. Anyone know Acura will replace it for me under warranty? I've only had the vehicle for 6 months (it was CPO and still under manufacturer warranty).

horseshoez

iTrader: (2)

A slight modification; when the A/C is on via the HVAC controls, the compressor *may* engage at any time the system thinks it is necessary; that said, on cooler days it is rarely on and on really cold days it will never be on.

When an O2 Sensor gets "lazy" it still looks operable to the OBC and as such, will not throw a light or code. This is true regardless of brand of vehicle; the same thing pops up from time-to-time in lowly Dodges up through high end Mercedes-Benz vehicles and pretty much everything in between. The thing is, O2 Sensors which are bad but not bad enough to throw a code are unlikely to get replaced under any warranty I've ever heard of.

Reorge

Did you check the MPG the old fashioned way? Miles driven/gallons put in tank at fill-up?
I would not troubleshoot an issue based on just what the ECU MPG value reads.

Also If you have the option "reset on fill up" set to enable, it can cause unwanted and random MPG resets and sometimes display erroneous MPG valves.

WNY PAT

I haven't reset trip B ever and that generally reads about 15MPG for me. But I drive my TL pretty hard, I'm not coasting ever.

wangjt

I've done it both ways by looking at the ECU and calculating it based on miles traveled/gallons filled (I have an app that does the calculating). There wasn't a significant difference in the numbers. They weren't exact but they were were off by 0.1~0.2 MPG.

I'll get the O2 sensor checked within the next few weeks.

deanoatkinson

15 MPG city stop and go, seems to be correct going under 40 mph that what i'm getting. But on the Highway i'm getting 26-27 mpg going 80-90 mph

ronricks

I seem to get the best gas mileage going 80 mph I drive mostly highway and get right around 30 mpg's. Have a 2014 shawd

TVL65

Going to replace the O2 sensors for sure

losiglow

iTrader: (1)

Yeah, oxygen sensors wouldn't be a bad idea. Remember to get Denso or OEM. Not aftermarket or bosch or anything like that. A good tune-up would be in order if you haven't already. New spark plugs, oil change, air filter, transmission fluid drain and refill, that kind of stuff. My FWD typically gets around 23-26 around town and 28 to 29 on the freeway. The sh-awd is bigger and has a larger engine but it shouldn't be that much different.

bboldea

I have an 11 SH. Awesome car with good mileage. I've owned the car for a few years now (bought this in place of a 1997 LS400).
I bought the car with 20K'ish miles. Now it's at 73K. Other than maintenance, NO issues.
The Lexus with a 4liter V8 used to get 21 to 22 MPG. The Acura gets quite a bit better, I've seen as high as 26 on highway driving only.