We now have several thousand miles on the FJ80 with the I-5 H3 motor in it. Highway mileage is averaging in the mid-19s, which is at least 30% better than the 3F-E.
The big change is in "in town" commuting mileage, though, with trips to the office, to shopping, in city traffic and suburban driving. With the stock truck, the "low fuel light" could pretty much be counted on to come on between 200 and 205 miles, taking about 20 gallons of gas. With the Atlas motor, under the same conditions, I can pretty much depend on 315-325 miles of range before the light comes on-- For in-town usage the mileage is considerably better.
I'm still pretty sold on the conversion, with the caveat that I'd have used the I-6 if the truck was going to be used more for towing.
The big change is in "in town" commuting mileage, though, with trips to the office, to shopping, in city traffic and suburban driving. With the stock truck, the "low fuel light" could pretty much be counted on to come on between 200 and 205 miles, taking about 20 gallons of gas. With the Atlas motor, under the same conditions, I can pretty much depend on 315-325 miles of range before the light comes on-- For in-town usage the mileage is considerably better.
I'm still pretty sold on the conversion, with the caveat that I'd have used the I-6 if the truck was going to be used more for towing.