After months of looking I finally pulled the trigger today on a 2000 F650 with a 3126B CAT engine. It is the Super Duty XL version with automatic transmission and air suspension in the rear. Rated at 26,000 GVWR with a 12 ft flatbed and around original 60,000 miles. Not sure what the truck weighs but is seems it would probably run 12,000 Lbs or so. It has hydraulic brakes. Does anyone have experience with the CAT 3126B engine and what can I expect for mpg? I plan to use to haul lumber & logs as well as to pull a large equipment trailer . Any advice will be appreciated.

 

I'd venture to say you should gat almost 10mpg from it, but that's a ballpark number. Gearing, and driving habits also come in to play with mpg. Not a whole lot of 3126 Cat fans out there. It wasn't their best specimen, but usually gives little trouble when maintained well.

 

I would be happy with 10 mpg with a reasonable load. I did find online an F650 specificaiton and it lists curbside weight for the chassis at 9,000 lbs and if that is true even with adding the 12 ft aluminum flatbed shouldn't be much more over 11,000 lbs? If yes that would give a solid payload since rating is GVWR at 26,000. Does that sound about right for this F650? It has a WB of 179 with the standard 210 HP CAT 3126. I do see a lot of 3126 engines out there but it is not good news if its performance has been poorbut with only 60,000 miles hopefully she will hold up well.