Hey, I was just out that way a few hours ago...picked up a super-yuppie at her weekend/family home near Auburn and took her to her commuter house in Santa Clara
(apparently, she pays my company $275 one-way to take her between these two houses every week 
)Isn't that a bit slow for you?
Back to the original topic, there are a few variables that determine mileage. I keep super-**** logs of my fuel economy, but I don't have a tach, so I'll just list how the vehicle's configured and the resulting mileage
My old '84 E-350 (long gone
) had a 3.54 rear end, a C6, and 31" BFG tires, and averaged 13 to 14 mpg in mostly freeway driving. The previous owner told me that he averaged 17 mpg with the original tires (he put the BFG's and new rims on the van a while before selling it to me), but I can't confirm that.My '84 F-250 averaged between 14 and 15 mpg before I made any modifications. From the factory, it was a 6.9l/T-19 with 4.10 gears. After I added the turbo, the mileage went down to 12 to 13 (I think part of that was the grin factor and part was different injection timing). After swapping the T-19 for the ZF5 I have in the truck now, I'm averaging 17 mpg. If I do a straight freeway run and keep the speed to 55 mph, I can do 20.
These are all with an unloaded truck, weighing about 7K. I've really only done one extended haul with the truck (towing a 4K boat {plus however much the trailer weighed} to Washington State and back last August; this was after the turbo/tranny) that I could get reliable fuel economy numbers from, and averaged around 14 mpg, and obscene EGT numbers...me wants an intercooler!!
