Hello new here with a fuel mileage question.

[Joe30690]

Hello, just got a 2006 XL f-350 with a 6.0liter and an automatic. Do these motors take a while before they get a good mile to the gallon? Right now its getting 12.98 city/highway. Seems my 2004 with the 6spd stick got a lot better mileage between 18 and 18.5 city/highway. I can't remember what the fuel mileage was when i first got it...

[mschn99]

How many miles on the truck?? It is very common to have considerably lower milage till the computer learns your driving stratagy and builds adaptive stratagy of its own...

AND welcome to the forum!!!

[Joe30690]

Hello thanks for the reply, it has 370 miles on it. Just got my second tank of fuel haha.

[mschn99]

i would expect for the next 6-10 thousand miles the milage will slowely improve to till it finally peaks....

[Joe30690]

Alrighty thanks. i kind of remeber that with my 2004 XLT 6.0/6SPD f-350, but then again i didnt pay much attention because the fuel was only $1.70 a gallon at the time...

[mschn99]

manuals dont tend to start off as low to begin with, because they dont learn tranny stratagy, just engine stratagy. The autos learn both...

[Joe30690]

Alright sounds good. Can a dealer tell if you use a Bully dog power pup if you were to bring your truck in for service? How long would i have to wait to use something like that on a new motor? Thanks.

[datsun66]

Ok, Talking about mileage.
I drove my 99.5 F250 4X4 with a 30ft rv for 160 miles with about a 25 mph head wind going up and down hills and runnung on B20. I got 9 mpg, would that be normal?

[Clay Henry]

Originally Posted by Joe30690

Bully dog power pup if you were to bring your truck in for service? How long would i have to wait to use something like that on a new motor? Thanks.

YES.
Wait untill your comfotable possibly givign up your warranty. You hava 5 year, 100k mile warranty on that engine.
Not all dealers will hassel you over those things but others will find any excuse not to warranty it.

[Clay Henry]

Originally Posted by datsun66

Ok, Talking about mileage.
I drove my 99.5 F250 4X4 with a 30ft rv for 160 miles with about a 25 mph head wind going up and down hills and runnung on B20. I got 9 mpg, would that be normal?

That sounds normal. The bio-d alone will lower fuel milage a tad. Add in the headwind, hills and load and yes, 9 sounds about right escpesially if your cruising above 70 mph.