Ford Powerstroke Diesel Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Just wondering if anybody out there has done this. My 7.3, 3.76/1 Excursion is used as a street machine with monthly pulls of my boat and WellsCargo auto hauler. But most of the miles are pulling an empty Excursion over relative flat country. I'm considering installing a GV OD just to increase my MPG and pulling power. Has anybody out there done this. Any thoughts?
All suggestions based on experience will be recived with thanks.
 

·
Registered
Joined
·
3,035 Posts
How far down does it drop the RPMs? I know in my truck with 35s, it dropped the highway RPMs to the point where at 60 MPH, you don't have enough boost, and your EGTs go up (more fuel to maintain speed). 66-68 MPH is better, about 550*, 1700 RPM, and 2.5-3 lbs, seems to be about the sweet spot.
 

·
WWW.COMPIGNTECH.COM
Joined
·
8,777 Posts
I think diesel power mag did a review on how to get the best fuel economy out of the 6.0l (yes I know your wondering about the 7.3) My point is that they found that with the 6.0 the best fuel mileage was achieved at around 1960 rpms right in the middle of the torque curve. When they installed the gear vendors overdrive it dropped the rpms out of the peak torque curve for the final drive ratio and caused the engine to work harder to get the truck down the road thus lowering the MPG's. They said that even though the rpms are lower the lugging was worse for the MPG's as it had to consume more fuel to gain the power needed to pull the truck at the given rpm for the speed traveled.

Even though 1960 rpms sounds high thats actually the peak efficiency rpm range on a stock 6.0l with 3.73 gearing to where the engine has the least amount of strain to produce the most amount of torque.

Not trying to sway your opinion of their setup just trying to tell you what I read about it.
 

·
Registered
Joined
·
2,542 Posts
I agree 2 k is the sweet spot.y truck gets better mileage at 70 then 55. So to hold 2k with a gear vendor you would have to set the cruise at 100 :hehe:

My uncle put one on his obs but it has a 460 in it. Gained a couple of mpg.


Sent from my iPhone using Autoguide
 

·
Registered
Joined
·
3,035 Posts
Who was the guy on the forums with the lowered 2wd, zf6 truck with the crazy camper/tonneau cover? He installed a gear vendors on his truck, and always preached about getting the perfect boost and egt ratio. He got like 26-28 MPG if I remember right.

On a lightweight, 2wd truck with small tires (like his), I can see it being beneficial. But add in the extra weight of 4x4, an Excursion, and larger tires, and I don't think it would be worth it...?
 

·
Registered
Joined
·
90 Posts
Who was the guy on the forums with the lowered 2wd, zf6 truck with the crazy camper/tonneau cover? He installed a gear vendors on his truck, and always preached about getting the perfect boost and egt ratio. He got like 26-28 MPG if I remember right.

On a lightweight, 2wd truck with small tires (like his), I can see it being beneficial. But add in the extra weight of 4x4, an Excursion, and larger tires, and I don't think it would be worth it...?
His name is "Big Dave" & can be found on ecomodder dot com. I've read a bunch of his posts & because of him I'm seriously considering doing the same.
 

·
Premium Member
Joined
·
84 Posts
I have a GV overdrive behind a zf6 4.10 gears and I am turning 1700 rpm at 70, I get great mileage. I have 50k on the unit with no trouble.
 

·
Registered
Joined
·
4,483 Posts
Friend is getting 20 in his 07 V10 with one
 

·
Registered
Joined
·
827 Posts
Dang, that's really good for the V10. I had an 07 with 4.30 gears + 33's and it never saw better than 10!

I've thought about the GV OD for my 7.3, good to read this.


Scott
 

·
Registered
Joined
·
6 Posts
Just got a Powerstroke 7.3 with 166,000 miles on it and just bought a gear vendors unit with an adapter for a Borg Warner transfer case attached. Since I don't have a 4x4 I will need to get an adapter for a E40D transmission. Hopefully someone on the forum has an E40D adapter they would like to exchange for the Borg Warner adapter.
 

·
Firewood Hack
Joined
·
191 Posts
I would like to try one on my fat bottomed girl. If I keep her around 55-60mph she gets around 16-18mpg (12-17mpg towing). If I'm traveling 65-70mph it's more like 12-14mpg, 1-4 less while towing. and that's on the "stock" tune. If I crank her up it gets worse mainly due to the 4:10 gears and the fact that she's 9360# fully fueled and otherwise empty with her overbuilt flatbed. She'll definitely pull harder after 2K rpm, but she's also thirstier. She has 214K on the clock and has never run better.
 
1 - 12 of 12 Posts
Top