Quote Originally Posted by kitz
Maybe not. Assume your V10 gets about 10mpg. At $3.56 you are paying about $0.35 per mile. The turbo diesel with chip I have seen get 18 mpg. At $4.50 this is $0.25 per mile. Diesel still more cost effective in general due to mileage advantage.

Kitz
That's correct - that is until you start adding in the maintainance factors along with a few other items, the diesel listed first i.e. (and these prices are for Fords, I assume Dodge and Chebbie are similar):

This is every 5K miles, or $220 vs $50

15 quarts of lube oil vs 7 ($75 vs $35 - Mobil 1)
$60 fuel filter vs a $10(same brand)
$20 Oil filter vs a $5 (same brand)
$65 fuel/water filter vs 0


An air filter yearly, $60 vs $15

Then a JIC of a load of crap fuel or gas
$300 each fuel injector vs $300 set

The gasser, spark plugs every 100K, or ~$60, and maybe a a COP at $40

Now, the big killer to add to that, an $8800 base price premium for the diesel. Even a 2 year old used truck - 4-5000 more.

Then add in the payback period for a $400 to $700 chip. I can't even consider that for my truck as the last time that I looked within the past 2 months, no one offered a reliable chip for the 3 valve V10 engines, regardless of any advertising hype. I can install a Banks cat back exhaust - that's it for reliable mods. So to put it on an even keel, no mods, factory stock, the dual turbo '08 and later 6.4 Ford turbos = 10 -12 mpg. Maybe. Same as my open road mileage.