Took a short trip mainly by Interstate of several hundred miles and checked my NITRO’s highway mileage for the first time. Fairly impressed, since it averaged 19.6 for the whole trip with the A/C on. One thing I did notice was it did not like 75 MPH and lost about 1 MPG over driving 60 MPH. This I suspect will change in the future when Chrysler has a 6 speed AT like my Wife’s Ford V-8 SUV, instead of the present 5 speed in my R/T. Adding a sixth speed is like adding a overdrive gear that really increases mileage at a higher highway speed. Think I read that Ford plans to use only 6 speeds in the future to increase their mileage and Chrysler should follow suit. I also am very pleased with it's ride at 75/80 MPH with no vibrations. Again, I am glad I bought it, not only for it's looks!

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Rick

Nitro Year: 2007 (July 07 Build Date)
Nitro Model: R/T
Nitro Drivetrain: 4x4
Nitro Color: Stone White
Fully-Equipped w/all factory options

i get now after the first service 20000km/32000miles about 30mpg highway
60-65miles/h and 25miles with mixed driving
automatic and diesel engine.

After first two months and 4000 miles, I'm getting 17.5 mpg in mixed driving. Florida mixed is some highway, but mostly secondary roads with traffic lights about two miles apart. Air Conditioning always on.

All highway is about 23.5.