I'm soon going to get my first fifth-generation GC after almost a decade of owning and self-maintaining third and fourth generations. I've decided to go for 2011+ and the 3.6, but if it has no edge over the 4.0 I'll save at least $3,000 and get a 2008. They both have the six-speed.

Has anyone done tests on either?

Looking at the EPA site it looks like a 2011 with the 3.6 doesn't do any better than my 2003 with 3.8 and 4-speed which gets 19MPG avg according to the console display..

http://www.fueleconomy.gov/mpg/MPG.d...rue&details=on

 

I have a 2011 3.6 Flex Fuel Pentastar. When it was new I got 19 city/25 highway. It has not been as good recently, but I just had the TIPM replaced, and it seems to run much better now, so I should be back to normal mileage again. I'll check it next week when I go on an extended road trip.

WORD OF WARNING! It seems a lot of 2011's have faulty TIPMs. I would avoid that year model.

 

My '03 does that with higher gear ratios and no VVT.. Kind of disappointing..

 

Our 95 averages 24mpg. It's very disappointing...

 

I'll get a '08 with the 4.0

Only because the better interior construction and less lines to trap rust on the exterior. I've found them for 4k before. The headliners and dashes in 4th gens fall apart too easy..