1200 mile trip - time to make changes

[wmoguy]

Just got back yesterday from a 1200 mile trip over the course of 3 days. Overall the truck did very well with no problems (thank god)

My mileage averaged 14.89 on the way out. with my cruise set @ 70 and a super strong head wind. Coming home I set the cruise at 65, which is actually more like 70 with my tires, and I avg'd 16.2 (naturally had a headwind again.......) I'm spinning about 2300 RPMs @ 70 mph and want to get that down.

I've been thinking about a Brownie box but not super stoked about having a 2nd shifter in the cab (wife could never drive it) and not super impressed with those Gear Vendor boxes. Has anyone tried installing a Roadranger transmission on our trucks? IIRC these 7.3's mate to a SAE 2 bell housing right? Does anyone know of a truck trans that has about a .55-.60 OD gear? I think thats where I'd like to be (and have all the gears in between too)

As for mileage, does 16 on the highway sound low? Like I said, cruise was set and overall the route was pretty flat miles.

 

[icanfixall]

Thats really not bad mileage for a 4x4 and 4.10 gears. My trip home from the 2008 ralley at 80 to 85 mph in double overdrive got me just short of 19 mpg. The 3.55 and GV gave me a final drive ratio of 1.96. This was the rpm at 85 mph...

 

[bab029]

That is my favorite pic ever.

 

[wmoguy]

thats SWEET Ican!

I'd be happy as can be to be sitting at around 1800-1900 rpms @ 75 mph

 

[jonathan]

i get 17.5 mpg going 70 with the cruise set and a double dose of the white bottle power service

 

[wmoguy]

i get 17.5 mpg going 70 with the cruise set and a double dose of the white bottle power service

not bad! what gear ratio does your pickup have?

 

[ManicMike]

16 does sound a bit low honestly. Espcially for a turbo'd engine.

Only differences I see between our rigs is your's is a crew and has the d60 up front. Mine's is a single cab n/a with the lighter d50 up front, I'm also a 4x4 (4.10 ratio) but have the E4OD trans.

I usually cruise with the rpm's between 2000 and 2300 (this put's me between 65 and 75). I regularly get 19mpg on the hwy.

 

[wmoguy]

16 does sound a bit low honestly. Espcially for a turbo'd engine.

Only differences I see between our rigs is your's is a crew and has the d60 up front. Mine's is a single cab n/a with the lighter d50 up front, I'm also a 4x4 but have the E4OD trans.

I usually cruise with the rpm's between 2000 and 2300 (this put's me between 65 and 75). I regularly get 19mpg on the hwy.

oops I should clarify my truck is currently a non-turbo truck.

I'm feeling like the truck needs timed and may be part of the issue as well

 

[jonathan]

not bad! what gear ratio does your pickup have?

it has 4:10s and the tires are a 245/75/16

 

[IDIDieselJohn]

Yours tires are abit smaller than stock.

Go for some 235/85's, that'll raise your gearing abit more, and skinny tires, less rolling resistance = more mpg.

 

[MR.T]

...As for mileage, does 16 on the highway sound low? Like I said, cruise was set and overall the route was pretty flat miles.

I think your about par running at 70, mine is similar running 70-75. I managed to break 20 on a recent trip (~1900 miles) by keeping the cruise speed down around 58. Gears can make quite a difference, as Icanfixall has shown (nice pic BTW).

 

[wmoguy]

I have 285/75 r 16s on my truck. Bfg all terrain ko's. Come to think of it they probably aren't helping. I was thinking larger tire when I bought them mainly to get my actual ratio down. But I am wondering if I am forfeiting any gains there with added drag from width and rolling resistance.

 

[Diesel JD]

About the brownie, it may be that your wife could drive it if she wasn't too intimidated by what it is. If you aren't towing heavy you could probably just select high range from a stop and she's never have to split gears. If you're towing or hauling very heavy then disregard what I just said. I haven't heard of a modern bug truck tranny behind an IDI, but I have behind a Cummins. It should be doable, but it would be a heck of a project.

 

[WilltheThrill]

i get 17.5 mpg going 70 with the cruise set and a double dose of the white bottle power service

what is this?

 

[RLDSL]

My wife can drive my truck , I'll just pop the brownie in OD and leave it, she doesn't have to touch the thing ,she just doesn't have teh extra gear options, but she couldn't shift that fast anyway.
Anotehr good option would be a spicer 7 speed EZ shift, this is a 7 speed fully synchronized box, Very sweet box would give you a lower bottom end and extre gear in between and shakes up the gear splits to better spots than with the 5