I have multiple vehicles. Each has a log book inside where I log everything from oil changes, windshield wipers replaced, fuel added, etc. A couple times a year I enter the fuel stats into an Excel spreadsheet that calculates the actual fuel mileage. Over 26,000 miles my 4Runner has averaged 22.89 mpg. I've seen as low as 12 mpg when using 4Lo on trails, and as high as 27 mpg on level dirt roads.
My mileage is better than most people mainly because I live very rural and don't drive stop light to stop light - that's what kills fuel mileage. And the vehicle is stock - no big fat 10 ply tires, no crap sitting on the roof. Most of my driving is on dirt roads at 40 - 50 mph. I have been very impressed with how accurate the 4R's in-dash indicated fuel mileage is. Those in-dash fuel monitors on my other vehicles are usually 1-2 mpg optimistic, the 4R is usually dead on.
