what gears was your '99 runnin?

 

The Factory 3.73 with 35/12.50 BFG A/T's

 

I should have the 08 again tomorrow to finish up the NAV Install and I will hit the Interstate and see what happens.....

 

Thanks....

 

I have a f-450 with 4.30 gears. Computer says that I am getting 10.2 when hauling my 18k trailer. And when im not hauling 10.6 to 11.2. Depends on how you drive it if you keep it under 2000 rpms when accelerating youll get the 11.2 but if you dont you get the 10.6.

 

kimminau, finally took it on the turpike last night. here is the breakdown as close as I could figure. rpms could be off .25 to .50. The one you were looking for 75mph was 2400 rpms. here is the breakdown. 55@1750, 60@1925, 65@2075, 70@2250, 75@2400, 80@2600, 82@2750. could not believe how stable it was at 82 felt like it could have gone a 100 easy but that speed governor sure kicked in. pulling our camper I usually had to run about 72mph in my 99 to keep it in the torque range of the v10. plan to run at 65(speed limit) with the 450. not sure in the tow mode if it will still just run 2075@65 or if the computer will kick up the rpms, probably depends on the hills. Had my first fill today 30.37 gallons @ 360 miles. computer showed 12.4mpg calculator 11.85 mpg round town and rural. of course 82mph last night for a bit probably did not help( but it felt good)

 

Thanks a bunch for doing that and posting it, firehawk198. That is very helpful information. It also makes me feel better about my selection of 4.30s on my order.

 

So I just hit a 1000 miles on the truck and I am seeing 12.8 mpg at its best, and that's mostly freeway driving. I have the 3.73 hear ratio with the AFE intake, and 4" custom exhaust to a 5" tip.

Nick

 

I just filled up with just under 1/2 tank left and 254 miles on odometer and it took 17 gals to fill up for about 14.94 mpg (calculated, computer said 14.3). It was about 65% hwy and 35% city, so my mileage is getting better. I have about 1350 miles on the silver beast and loving her still!

 

Thanks... very helpful. I am actually thinking about just having the gears changed to 4.30 now. At $350 per tire, 6 of them is $1,950, I can have the gears changed for $2,000 or less.

 

I have an 08 F-250 Crew Cab 4X4 Long bed with almost 2,000 miles on it. I drive about 1/2 freeway and city and the best MPG I've got is 12.5 The computer has never shown higher than 10.5. And, I'm not even pulling anything either. Although in Socal its hard to cruise at 65 mph on a freeway for very long.

 

Actually, I think I am going to hold off a little while before doing anything. I have about 5,500 miles on her now and my mpg just keeps creeping up. When I first started towing with her I was at +/-6.5 mpg, actually towing heavier loads now over the same roads and I am getting pretty close to 9 mpg right now.

 

I drive a diesel near everyday so I am hard to fool when it comes to MPG. I do have a 05 gasser now because I would not buy the 6.0L, my choice.. I am considering the 6.4l . My truck is a work truck its work is pulling a near 13K 5th wheel all over the country.We are not all that concerned with MPG but as I read these post I see numbers all over the place and I wonder??? Most folks i know that pull in that weight range average @ 9 to 12 Diesel.. I get 7.5 to 10 with the V-10 .Now someone will post they get 15/16...right... There are two areas that folks have a hard time with the truth..when they are doing their taxes..and when they are telling about their MPG.

 

richfaa, also my v10 averaged 7.5 to 8.5 towing 13,000#. Upgraded to a 450 with 4.30s planning an upgrade camper of 16,500 also. Can not comment on towing milage yet, but the comfort and quietness in the new 6.4 is amazing like kimminau said milage improves as it gets broken in.

 

I would be suprised if you see much of a change in the mpgs,my 6.0 has never got any better, these high reving engines are not made for mpgs. It seems the big three are only thinking about who has the most hp and thats it.