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-   -   My MPG is embarrassing to mention. (http://www.jeepgarage.org/f5/my-mpg-is-embarrassing-to-mention-10070.html)

venusfan 06-07-2010 01:25 AM

My MPG is embarrassing to mention.
 
I have a '05 WK V8 RM 55K and everyone is good except the MPG. Right now I'm getting a shameful 7.8 MPG city and if I jump on the highway for 10 miles It may go up to 10-11MPG.

I had the fuel injector cleaned and some crap the oil change people told me I need to clean in the engine and nothing has changed. I would like to know what can I do to improve the fuel consumption. I got the car 13 months ago and the MPG has always been pathetic but now I cant take it anymore.

I'm not a mechanic so I really cant do anything myself so odds are I'll take it to a shop and even worst the dealer. Thanks everyone but if I can just get 13MPG city I will be okay because I'm seriously thinking of trading the car in for a GMC terrain.

Mike_Levy 06-07-2010 01:29 AM

Re: My MPG is embarrassing to mention.
 
My last tank was 5.5mpg. As you can see below, my average ain't much better.

I'm not embarassed though. You gotta pay to play.

S.O.T.I. 06-07-2010 07:07 AM

Re: My MPG is embarrassing to mention.
 
Quote:

Originally Posted by venusfan (Post 218086)
I have a '05 WK V8 RM 55K and everyone is good except the MPG. Right now I'm getting a shameful 7.8 MPG city and if I jump on the highway for 10 miles It may go up to 10-11MPG.

I had the fuel injector cleaned and some crap the oil change people told me I need to clean in the engine and nothing has changed. I would like to know what can I do to improve the fuel consumption. I got the car 13 months ago and the MPG has always been pathetic but now I cant take it anymore.

I'm not a mechanic so I really cant do anything myself so odds are I'll take it to a shop and even worst the dealer. Thanks everyone but if I can just get 13MPG city I will be okay because I'm seriously thinking of trading the car in for a GMC terrain.

Fuel efficiency has never, EVER been a Jeep strong point. You're in the wrong make of vehicle to be concerned with that. I'd hate to see you flip to the dark side, so on to your problem...

The single greatest factor in poor gas mileage is driving style. Obviously heavy acceleration, stop and go, lots of city driving, etc. will kill your mpgs. Be honest, you have a V8, so you drive it like one, eh? ;) You really have to drive it like a granny to get any decent mileage. I don't know if it's changed, but back in the day, mpg's were calculated on a track with a test vehicle traveling 45 mph in a VERY controlled environment. I thought I had read somewhere the government is demanding more realistic estimations.

ekaz 06-07-2010 08:22 AM

Re: My MPG is embarrassing to mention.
 
My 426 gets somewhere around 10-11MPG in combined city/highway driving so something may be off. How many miles do you have on the Jeep? Have you checked/changed the air filter? Spark plugs? The gas you are using can also play a role.

UTJeffC 06-07-2010 08:49 AM

Re: My MPG is embarrassing to mention.
 
Quote:

Originally Posted by S.O.T.I. (Post 218107)
I thought I had read somewhere the government is demanding more realistic estimations.

They test them in fairly realistic circumstances, and have for a while. I have found that it is possible to meet and exceed the rated estimations as long as you don't have a lead foot.

http://www.fueleconomy.gov/feg/fe_test_schedules.shtml

White Chocolate 06-07-2010 08:57 AM

Re: My MPG is embarrassing to mention.
 
I get roughly 11MPG in the city, and 15-18MPG on the highway!

LOL, pay to play yup!

BIG-O 06-07-2010 09:23 AM

Re: My MPG is embarrassing to mention.
 
I get 11-12 city and 16-18 highway and i have a freaking v6!!!!

Robert Palmer 06-07-2010 09:39 AM

Re: My MPG is embarrassing to mention.
 
MPG? Que? :D



(inside joke)

S.O.T.I. 06-07-2010 09:41 AM

Re: My MPG is embarrassing to mention.
 
Quote:

Originally Posted by Robert Palmer (Post 218160)
MPG? Que? :D



(inside joke)

With the way people describe your driving, I would imagine it's more like gallons per mile, not miles per gallon! lol

blackpepper 06-07-2010 10:46 AM

Re: My MPG is embarrassing to mention.
 
Change your plugs, I saw the best improvement in MPG after I put in new spark plugs.

Quote:

Originally Posted by Robert Palmer (Post 218160)
MPG? Que? :D

Aways on point, never on time.. :D

no-blue-screen 06-07-2010 11:19 AM

Re: My MPG is embarrassing to mention.
 
Is this the Hemi? If so, are you using regular (87) or plus (89). IIRC the manual calls for 89 octane fuel. You can run 87 in it, but this will result in reduced performance and fuel economy.

The estimates I see are 15/20 for the 4.7, and 14/19 for the Hemi assuming 4x4. You are not too far off if you had an SRT8 with the 6.1, but some other things to check would be as follows:

-Tire pressure - Generally speaking your fuel economy suffers about 3% for every 1psi below spec. My 08 calls for 33 and the standard now is 35psi. I run slightly higher at 37psi.

-Brakes/parking brake - Check these items. Sticking brakes or a mis-adjusted parking brake will kill your mpg and ruin your brakes very quickly.

-Ditto the plugs and filter. IIRC Jeep does not use the platinum (100k change interval) plugs in these vehicles....but don't quote me on that.

Also, like was stated driving style has a lot to do with MPG. Constant speed changes and excessive brake usage will result in very poor fuel economy.

gc4x4 06-07-2010 11:25 AM

Re: My MPG is embarrassing to mention.
 
Quote:

Originally Posted by venusfan (Post 218086)
I have a '05 WK V8 RM 55K and everyone is good except the MPG. Right now I'm getting a shameful 7.8 MPG city and if I jump on the highway for 10 miles It may go up to 10-11MPG.

I had the fuel injector cleaned and some crap the oil change people told me I need to clean in the engine and nothing has changed. I would like to know what can I do to improve the fuel consumption. I got the car 13 months ago and the MPG has always been pathetic but now I cant take it anymore.

I'm not a mechanic so I really cant do anything myself so odds are I'll take it to a shop and even worst the dealer. Thanks everyone but if I can just get 13MPG city I will be okay because I'm seriously thinking of trading the car in for a GMC terrain.

Check the plugs,air filter,pcv valve,make sure the oil grade is 5w20-it is required for the engine to run properly. Get a CAI intake and magnaflow muffler or whatever you like,the biggest holdback is the huge factory muffler on these. These will all help with your mileage.


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