I have about 21,000 miles on this vehicle. About 3 months ago I noticed the in-town mileage was decreasing and that I was having trouble starting the engine. The dealer said it was bad gas and I should start using Shell. The dealer said that regular was OK. The problem persisted and the dealer then said to use Chevron. I am now using Chevron high octane. The starting problem improved but I still get a rough idle. Gas mileage has continued to decline. I am now getting about 16-17 miles per gallon in town where I used to get a steady 20. Has anyone else had this experieince and if so did you find a solution?

 

If your style of driving have always been the same... then it's probably the grade of gas you're putting in. In other words, try using premium 93 octane or least 91.
I don't think Acura recommend you using regular gas......

 

Do not complain about your mpg
I am in New York and I get 12-14 mpg in the city.
However when I am on hwy I get 29-31 mpg.
It is very strange, because most of cars out there do not show such dramatic difference in gas consumption between city/hwy
Enjoy TL

 

Maybe just try other brand gas until the problem goes away?

Things that impact MPG:
Tire pressure/type,
Ambient temps (colder is worse),
Driving style,
Driving conditions (stop and go, red lights)
Gas formulation (winter gas may not do as well as the summer stuff)
Octane, running low octane gas may trigger the knock sensors and retard the timing, giving lower power output and a decrease in mpg.
Having a dirty air filter.

Brett

 

Man, that's not good.. mileage, I mean. I regularly get 26-27 in town in the summer months and 25-26 in the colder months. My '04 TL is a manual tranny and I use Mobil 1 5W/20, burn Amoco (BP) 93 octane fuel, and treat my fuel system every 10,000 miles with Chevron Techron Fuel System Cleaner. I just crossed 20,000 miles this past weekend.

On the highway in the summer with A/C on and no special gas-saving techniques employed, I get just under 34 MPG (33.94).

 

It sounds to me like you are having a problem.. but the dealership is either unwilling to look for it or can not find it... most likely because it does not trip a code for them to see...

I have had problems on other cars and it is SO frustrating to keep telling them what to look for and then they come back with 'we can not find any code'.... like EVERY problem will trip a code...

Keep it up with the dealer and make them find the problem.... and I will be $$s it is not the gas...

 

I wonder if your air filter is dirty.

Check it...if it is...replace it.

OR install a cold air intake. There are now three options...INJEN, AEM, or FujitaF5.

Before I cleaned my air filter, I did 28 mpg on the highway. After I cleaned the filter I averaged 34 mpg.

 

I, too get about 16mpg in the city. I think it is important for people to define what they mean by "city" driving. I live in Chicago. I have noticed that when I am in the suburbs, my gas mileage increases to about 24mpg, and on the highway I get around 29mpg. I think that for those who are getting in the 20's for their City usage, that their definition be more strictly defined. I think that the stop and go of big city usage (New York, Chicago, etc) is just a big gas drain on that big V6 engine. Essentially you are using much more gas to get the car going to 40mph or so, then having to stop the car seconds after reaching that speed for yet another stop sign or traffic light. If anyone lives in a city like Chicago or New York with stop signs/lights every single godforsaken block and gets better gas mileage, pls let me know. I have been using only 93 octane, and am getting the same gas mileage as my 99Rx300 with 87 octane. Once again, that was a smaller engine.
HOpe this helps.

 

You're right in your assessment. My commute to and from work is through the town of Manassa, VA, a small city, nowhere in the league of Chicago or New York for sure. I go through both business and residential areas. My morning trip sees light traffic since I hit Manassas before 5:00AM. Coming home, I'm in moderately heavy traffic for the area since it's around 3:30. Takes me about 1 hour to get home in the afternoon and about 45 minutes for the morning run.

I'm pretty confident I could see high teens to low 20's in a large city because of my driving style. But it wouldn't be any 27 MPG I'd bet.

 

Your gas usage is mostly dependant on your acceleration habits. This is the one factor that has consistently shown huge gains when using less gas to get going from a stop or getting onto a highway. I tend to push the car hard becuase it's fun, but easing off from a stop or slow speed will improve gas mileage by leaps and bounds. Your top speed isn't what does it, it's more of how you got there.