Bad Gas Mileage!!!

[cp-the-nerd]

This is why I never buy bargain gas, and why I insist my girlfriend does the same. Always buy from good brand names like Shell, BP, or Exxon. I also change my oil within 5000 mile intervals and use fully synthetic oil.

I haven't been driving forever, but I drove an 89 Camry from 50k to 120k miles without ANY loss in fuel economy or need for injector cleaner, and 45k flawless miles in my Malibu V6 achieving 18/28 mpg.

[dowell69]

Seems like the same story all around. When I started this thread My 2012 had 4000 miles and now I have almost 11000 miles and nothings changed. city driving gets me 20mpg and the best HWY driving has ever gotten was 29mpg. AND YES this is using the best fuels and trying to drive as efficiently as possible. I still like the malibu I just wish I would have gotten the V6 so at leat with the bad gas milage I would get a little pep. thx for all the posts...

[DrivenDaily]

At 29 mpg, have you lifted the hood to make sure it's a 4 and not a 6? Just seems odd that you can't get mid-30's like so many others.

Heck, I even got 36.4 one time and one time only (so far) while driving 60 mph from Knoxville, TN, to Louisville, KY. It was October 2011, and it was 234.8 miles using just 6.453 gallons. Funny thing is my trip meter said 234.8 and my odometer difference from the previous fill-up was 264 miles. I must have written down one or the other incorrectly, and I think it was the previous odo. The DIC indicated 36.5 when I filled, so when it calculated out to 36.386 mpg I was elated! And it only took setting the cruise on 60 and then just steering it. I only had to get up to 65-70 a time or two to wiggle out of heavy traffic, but then I took my foot off the gas and settled back into 60. I'm gonna try it again someday, not sure when, and see if I can get it again. I don't consider it an anomaly, but instead it's a rare event that I drive less than the posted speed limit.

If I calculate driving only 234.8 miles on 6.453 gallons I get my posted 36.386 mpg. However, if I use the odo difference (rounded to nearest mile) of 264 on the same fuel, it calculates out to 40.911 mpg. I highly doubt I did that good on a V6, but if I could do it again I'd reconsider that statement!

[MyBu08]

Just bought an 08 Malibu V6, 50k mi.
Full tank last night, drove to work and back (60miles), gym and back (maybe 10miles) and now down to almost a half tank...WTF! This doesn't seem anywhere close to what it's suppose to be doing. I had an 02 Impala b4 this with the 3.4 and got close to 28-29 highway with 160k miles on it...
Should I be looking into returning this car???

[cp-the-nerd]

Originally Posted by MyBu08

Just bought an 08 Malibu V6, 50k mi.
Full tank last night, drove to work and back (60miles), gym and back (maybe 10miles) and now down to almost a half tank...WTF! This doesn't seem anywhere close to what it's suppose to be doing. I had an 02 Impala b4 this with the 3.4 and got close to 28-29 highway with 160k miles on it...
Should I be looking into returning this car???

Does the fuel economy readout also say you're getting terrible fuel economy? Use midgrade or better gas, maybe get some injector cleaner, make sure the oil is changed and using fully synthetic oil as recommended by the manual (Dexos 1 certified). It may have been abused during its ownership.

[DrivenDaily]

Originally Posted by MyBu08

Just bought an 08 Malibu V6, 50k mi.
Full tank last night, drove to work and back (60miles), gym and back (maybe 10miles) and now down to almost a half tank...WTF! This doesn't seem anywhere close to what it's suppose to be doing. I had an 02 Impala b4 this with the 3.4 and got close to 28-29 highway with 160k miles on it...
Should I be looking into returning this car???

Originally Posted by cp-the-nerd

Does the fuel economy readout also say you're getting terrible fuel economy? Use midgrade or better gas, maybe get some injector cleaner, make sure the oil is changed and using fully synthetic oil as recommended by the manual (Dexos 1 certified). It may have been abused during its ownership.

Or maybe it pointed to Full but really wasn't!

Or maybe the sender has an issue and it's not reporting the correct level.

Before spending money or embarrassing yourself at the dealer try filling the tank yourself and driving it until you need gas again, then check your mileage. If it's within spec then maybe the salesman told you that you'd get a full tank but lied to you by putting in just enough to have it point to full.

Not that any salesman has ever lied to anyone. No, that's unheard of!

[MyBu08]

Oh I filled it myself Sunday night expecting to only need that gas for the week, like I normally did with the impala. It was reading 20-21 average mpg...it's 99% highway driving for me to work and back. I don't like this at all! lol Could have got a truck with better mpg than that.

[MyBu08]

Managed to get 27 avg mpg this morning...soooo IDK!

[greenman]

Only way to know if the engine is maximizing fuel efficiency is to put a scan tool on it & look at the EFI fuel trim data. The EFI system could be dumping in excess fuel to compensate for a lot of potential problems but you won't know without looking.

[cp-the-nerd]

Sounds like it was premature complaining! No offense, haha.

Get to know the car and go through a few tanks and report back to us. Also, you should still follow the tips we laid out for achieving good FE.