Best milage?

I just drove from my farm in San Rafael to Buenos Aires, about 600 miles. I got over 18.6 mpg. I was running 5-30 semi-synthetic from YPF and using 97+ octane. I drive about 110 km per hour, about 64, with the air on and about 500 lbs of cargo, passengers. I'm very happy with my milage figures as gas, nafta, costs about 67 cents per litre, which isabout 2.25 per gallon for the best stuff. I took a 6,000 mile trip around patagonia and averaged over 16 mpg, with many 4x4 miles on dirt roads. Changed oil today to a total synthetic by shell of 5-40, yes I know you're not supposed to run it but I did for many years on another sub. Well what you highest mpg figures for real world driving? Oh, I have a 99 k1500 5.7 vortec motor 3.42 rear end w/posi.

67 cents a litre is cheap IMO. It's 95 cents a litre here.

My all time high for fuel mileage so far has been 16.8 mpg (US gallon)

81 Jimmy, 6.2 diesel, SM465 (no overdrive) 4.56 gears and 39.5" TSL's. Not bad for old iron without computers or overdrive...or good aerodynamics...or radials. :icon16:

Rene