That probably means when it's in 4x4 lock mode, which locks it in 50-50. I've heard that only applies to speeds of less than maybe 40mph, too. Does yours have the L on the shifter or the Autostick? If it's got the L and a Trail Rated badge, that means Freedom Drive 2 off-road edition and 25mpg is pretty good for normal driving on the interstate. If it's Autostick, that means Freedom Drive 1, and you should be getting closer to 30mpg at cruising speed. When not locked in 4x4, it's basically a front-wheel-drive based all-wheel-drive vehicle. Front wheels are always driving it, but if it senses slippage it can put up to 20-30% power to the rear wheels to help.

 

The MPG rating will vary depending on the drivetrain option you have. FWD models are rated 21/25 from your example above and 4x4 get a bit lower MPG as it is considered AWD/4x4 model. FDII gets even lower MPG as it has the low range option and the engine tends to spin at higher RPMs producing lower MPG. My 2010 FDI is rated 21/24 and 22 ave. My average over 40k miles has been 22.4 MPG. Note my Patriot is lifted with larger tires. When it was stock I could get 27 MPG hwy.

 

Thanks guys. I do not have the Trail Rated edition, I'm guessing I have the regular 4x4 edition with the autostick. I haven't had much time to actually test the MPG myself, I plan to get to doing it soon. I don't use 4x4 much so I'm hoping to get the 27+ mpg hwy when not using it.

 

I have a 2014 4x4 with the 2.4 engine and autostick, and around town, which I do more of than highway, I average 15 - 19 mpg, but I'm not a granny driver either. Last week I did a bit more long distance driving and got 25mpg. Your mileage will vary due to driving style, and now that winter is here, I find myself using remote start more often to get the Jeep warmed up, and windows thawed before I go to work in the mornings, so naturally the mpg is going to be lower due to more idling time. Weight is another factor, if you carry a bunch of extra cargo with you, like all the time, it may affect your mileage. Taking coolers and emergency gear with you when you offroad, or if you're planning on travelling in a snowstorm is a once in a while event. Wheel and Tire size may also affect mileage, both in unsprung rotational weight, and diameter. The mileage for the Patriot's was calculated using stock tires.
Another member did a write up on this, and it's in a sticky above, very informative.

 

Regular 4wd on the FD1 should get about the same MPG's as the 2wd version.

My 2.4L engine is great on my FWD Patriot, I get about 24 mpg average and I drive a lot of hills.

Another thing to factor is the wheel choice. My 17" wheels weigh significantly less than my 16" steel wheels. Both are oem style. With my lighter 17" wheels and tires I get much BETTER mileage than with my heavy steel 16" wheels. My all terrain tires don't help either. My 17" wheels still have the oem Firestone Affinity tires so they are pretty light.

Wheels are tires make a huge difference on any vehicle. Excess rotating mass is a huge parasitic draw on fuel efficiency.

 

When they test the MK's the don't have the 4x4 lever lock, and in the normal testing the 4x4 would hardly ever kick in. The difference in the ratings comes from the fact that in 4x4 models, the PTU is always routing power to the rear wheels through the drive shaft. The ECC clutch on the rear differential is what controls exactly when the rear tires receive power.

The lower ratings on the 4x4's comes from the parasitic driveline losses of having power routed through the power transfer unit and the driveshaft spinning.

The FDII models have even lower fuel economy ratings due to lower overall gears at all speeds.