This is a follow up to my last thread, LED (average miles per gallon).
I Recently bought my 2007 Aspen 5.7 Hemi with 4 wheel drive with only 33,000 mi into the Chrysler Dealer after trying numerous things to get better gas milage like,
Change air filter, useing fuel injecter additive, and keeping tires properly inflated. My truck runs fine smooth as can be only problem, I only average 9 miles per gallon. The dealer said thats what these trucks get. It upsets me that he changed my oil kept the truck for 4 hours and gave it back and said Everythings Fine now pay the cashier 38.00 for the oil change. The Clerk at the service counter says that normal for city driving with my aspen. To me thats not normal. I would expect to get at least 12 to 14 mpg . Does anybody have ideas what tests should have been done to my truck to determine that all is well at a dealer. I will try anything to get a few more miles per gallon. Thinking about changing plugs any ideas appreciated.

 

Have you changed the plugs yet? They're due at 30k miles. A fouled plug can result in poor gas mileage. I get 12-13 in the city.

There's too many variables for anyone to know what's going on with your truck. If you're doing lots of stop and go driving and idling, that greatly affects gas mileage. Your driving habits (how hard you hit the gas pedal!), whether you're using the a/c, type of tires (are they stock?), and even the type of gas you're using affect mileage. If you have the Hemi engine, you should be using midgrade gas. Using 87 absolutely will affect the fuel economy, and using premium is a waste of money.

Most other potential causes (e.g. EGR valve, bad injector, etc.) are unlikely on an engine with 33k miles.

 

Mixed City for us is 13.3 -- 15. That's with some freeway driving, but also stop & go and idling (while in line to pick up kids from school). Ours is 2wd, and we have aggressive AT tires. I'm guessing we would get 1mpg better with lrr tires. 9 is very low. I would frown also. However, I could see 9mpg if it were all city (small town) driving. How big is your "city"? Do you ever get it up to 60mph, &/or operating temp? I grew up in a small town, and my parents still live in a small town. Speed limits are 25-35. I'm guessing I'd get about 10-12 MPG if I lived there.

 

I get 14-17 mpg City.....I say go to a different dealer

 

I too don't get good gas mileage on my 07 Aspen. I was averaging about 10-11 in the city. Yes it was stop and go, commuting about 5 miles each way on city roads (no freeway). Now that I am commuting on the freeway every day I am seeing around 14-15 mpg. (Some stop and go on the freeway due to morning and evening congestion). I would love to see my MPG higher.

 

I have just noticed lately that my milage has dropped from 17-18 down to 12-13. I have been wondering myself on this. My Emissions box ( charchol) by the tank collasped on itself due to a faulty seal (not covered under warranty) I will check on the plugs.. I have 90k on the truck, but just supprised on the issues adding up in the last 10k miles.

 

I live in a city area and my typically avg is a 9-10. I changed oil revery 5000 miles and have kept the stock filter. Im thinking of changing over to the K&N one. But When Im back and forth on the freeway i have gotten up to 19 avg. I have the hemi engine as well.
Your in the ball park with your avg.

 

We are averaging 14-15 city, and get 18-21 on the highway depending on if it is flat highway or hilly.

 

Stick with your factory air box and paper filter. K & N, along with other oiled filters, let too much particulate through. Our factory air boxes aren't as restricted as other vehicles and get plenty of flow. All you'll be doing is gumming up your throttle body and letting dirt into your engine, which will cause you lots of problems in the long run.

 

Agreed. They should have checked your plugs as well. Heck, they could have/should have changed them out and charged you for them, too, and I am surprised they didn't.