10-14 mpg city on 2012 LT?? (video link inside)
 

Hi Guys,

For some reason (I expected my CAI filter at first but now not so sure) I'm getting horrible MPG this summer compared to last, but I don't think I'm driving any differently. Here's a quick video I took last night without driving too aggressively:

http://youtu.be/HL4KoL7txT0

Can this possibly be right? I'm consistently only getting about 10-14 mpg driving locally. If it wasn't for times of coasting with foot off of pedal I'd probably be in single digits. I have no idea what this could be. The car sat most of the winter; started summer with an oil change. I tried re-oiling CAI intake filter twice now, also used MAF sensor cleaner and tried ECU fuse pull for the hell of it. Nothing helped; only other mod within engine compartment is catch can.

Any ideas what would be causing such low mpg now when I haven't changed anything on the car since last summer? I'm not sure where to even start troubleshooting this.

Thanks.

Take the car onto the turnpike and reset the mpg gauge, then drive for about 20 miles to see what you get on the highway.

You can't go by little short runs, resetting your mpg readout. By that method, if you want to feel really good about mpgs, go out in the country and find a nice long downhill run. Reset the mpgs and drive a mile or so giving it just enough gas to gradually get into high gear. Your mpgs will be up around 40 or 50 (or more).

Seriously though:
Go fill up with gas. Reset your mpgs and your trip odometer and leave them alone until you fill up again. Drive "normally" for at least 200 miles and fill up again. Divide your miles traveled by the number of gallons it takes to refill your tank and compare that number to what the DIC mpgs reads. They should be pretty close, within 1/2 mpg or so.

I've been averaging about 23 mpg highway. Last summer I averaged about 29-30mpg on the same highways.

I'm not, this reset was just for purposes of a video. I'm judging from last summer to how it's been overall this summer. It's been something going on for the last couple of months now. :frown:

I see. Hmmmmm. Sounds like a job for the dealership to figure out. MPGs (especially in V6s) usually improves some after a year of so break-in (15K miles or so).

I have 15,000 on mine and the mpg has improved by about 2.

How many miles did you have on the CAI? And why on earth did you re-oil it twice? Sounds to me like you may have too much oil in the filter and it's fouling the mass airflow sensor or restricting airflow into the engine.

I would clean the filter and remove the excess oil, then re-oil the filter per the instructions. Clean the MAF sensor, and also remove the CAI intake tube and wipe out any excess oil that is in the tube, make sure you unplug the battery while you're doing this to reset the ECM. When you get everything back together, reset the mpg on the DIC and take it for a drive. It is also possible that you just have bad gas since the car sat all winter.

My thoughts....

Just a suggestion, you should post this in the LFX section, you'll probably get many more responses there.

I have a CAI inductions intake and glad I do not have oil like a K/N type, as I know the oil can foul the MAF sensor, and that's why other non oil filters are better. Oiling your filter should be done on a so many thousand mile basis like ten thousand to never.............. Never liked oil treated filters and they have given vehicle problems before......And a SS gets 12 mpg in city driving stop and go. and gas has a tendency to loose its oxygen content when sitting and maybe a little trip to the auto parts store for some octane booster is in order if your going to have it sit all winter.............

Agree with this. Go buy yourself a can of CRC MAF cleaner. Take her out on the highway and reset it and see what you get.

something not right .....that should of shot up to 30 plus with rpm less than 2000..

I almost thought that was a Mustang.

Thanks for all the tips guys. To clarify what's already been tried:

-I've 're-charged' the filter twice this summer thinking it may have been too much oil fist time around.
-Used MAF cleaner twice.
-Been using the car the last two months, so have gone through the gas that the car was sitting with and then some.
-My highway mpg has been around 23-25mpg, where as it was 29-30mpg on the same highways last summer.

About 5,000 -6,000.

I meant I did a full recharge twice over the last two months (as in full clean, then oil), suspecting that I might have used too much oil the first time around . Also used MAF sensor cleaner both times. I don't think it could be a gas issue anymore either since I've run through the gas and filled up a handful of times so far this summer.

Yea, I mean if I did the same type of coasting last summer the DLC seemed quicker to acknowledge and easily would have read something 30+. I'm stumped. :noidea:


Any other troubleshooting tips guys? I don't know how else to troubleshoot this issue other than what I've already done.

Thanks for clarifying... My only other suggestion would be to take it to the dealership if it's still under warranty.

Are you sure that happens in a short city drive?

With my V6 i get around 17-18 City Driving.
I took it on a long trip. Made 320 miles with half a tank (33 MPG more or less), awesome MPG in highway.