2008 F-350 fuel mileage comparison

[Bill]

I,m looking at buying a new 2008 F-350 supercab 4 x 4 automatic with 3.73 gears. I am considering the diesel engine. When I looked at my dealers inventory I was disappointed that fuel mileages are not listed for either the gas or diesel engines. When I enquired what the mileage was for both, they said they didn't have that info. In speaking to two pepole I know who have purchased new similar 2008 F-350 diesels, both complained of poor mileage under 10 mpg and thats without towing or hauling heavy loads. One brought his back to the dealer because he was concerned something was wrong. The service dept told him everything was o.k. and wait until after the 10,000 mile break in period to see what happens. Can you tell me what the estimated mileage is for both the diesel and 5.4L gas engine in the above discribed truck? If the gas engine gets better mileage then the diesel, I don't really do enough towing to justify poor mileage and $7,000.00 option cost. Thanks, Bill

[Diesel Engineer]

Bill, the fuel mileages are not listed because these are typically used as work trucks or for commercial applications and fall under the "above 8500# GVW rating" vehicles as per government requirements for reporting mileages. You can realistically expect to get approx. 10-11 MPG or so around town, stop and go type driving and about 13-15 on the highway with the diesel option, depending on many variables your mileage may vary more or less than these averages. If you are hauling heavy loads, expect to get less than that. Some vehicles, if they are not crew cab and 8 foot bed option can get slightly higher mileages. Also the type of fuel and lubricants you use can affect fuel economy, especially with the ULSD fuel. A Cetane Booster Additive as well as a Diesel Concentrate Additive to increase lubricity of the fuel is also required with the new ULSD. The 5.4L will get slightly better mileage, typically 11-13 around town up to 14-15+ MPG on the highway. The main benefit of the diesel engine is massive amounts of power and torque for pulling and hauling, far more than the 5.4L, plus the extra durability and longevity of the diesel engine. If you do not need that extra power of the diesel for pulling and hauling and you do not want to spend an extra $7000 for the diesel option then the 5.4L will be just fine for you. I hope this helps, Dave

[Ken's PS]

I have two friends with the 2008 diesels and they started out in the 10-11 bracket but are now claiming as the mileage increases on the vehicle that their gas mileage is improving as well and are now up to the 13-14 range on the freeway.
Kenny

[thompsonc]

I own an 08 F-250 and I'm getting 19-20 mpg average on the highway and 14 mpg average to and from work in the city. When i first got it, it was doing 14 mpg pulling my boat through the mountains. It now has 15000 miles on it and i now have Amsoil in the engine, transmission, differentials, and transfer case. Once it warms up out here, I'll take it on a longer trip somewhere and see if the mileage has improved any.

[horsehaulin]

A diesel engine needs to be pulled hard with a solid load to loosen up some and let the engine start to run good.

Tony