Gearvendors O/D F-550

[oxman202]

Before I bash Gearvendors I would like some of yalls opinions.

I just put the Gearvendors O/D on and went on a long haul. 70 mph on cruise 11.16 mpg loaded with a gross weight of 15,600 lbs. I thought not bad since I was getting 10.5 mpg empty.

90° temp outside, EGT 820-880°, Trans 172°, Boost 7-8 PSI and Water 198-202°.

Empty was 12.75 MPG same 70 MPH cruise. Same outside temp, EGT 790-830°, Trans 169°, Boost 6-7 PSI and Water 196-198°.

This was on the 165 hp canned tune. When I fill up it is pouring out pure diesel, no foam. That way I know it's full. All calculations are done by hand.

What gives 2.25 MPG for $3250, come on there has to be a reason why I'm not getting the 14-15 MPG that I was promised.

Any suggestions PLEASE!

I've never seen the estimates but I have driven 2 450's with the Gear Vendors OD behind a ZF 6 Speed. When in the top gear I would hit the GV OD and it would drop about 4-500 rpms. Where I was driving that put me right below 2000 rpms which is where I think the Strokes run the best. I realize that they are expensive cuz I was wanting one for an old chevy I have but I guess I personally wouldnt expect more the 2 or 3 mpg.

[lamarmathis]

i really doubt gear venders can promise any concrete mpg increase,id say its an up to type statement,all they can do is tell the gear ratio diff between and maybe cruise rpm,jmo

[oxman202]

Well I took this headach rack off and now I'm at between 2-4 PSI and about 770 egt. I haven't been able to go on a trip yet but will soon. I have just heard of people getting between 15-17 with my same setup at 70 mph. I'm also going to take the broken 1000 lbs. lift gate off that I never use.

[oxman202]

Well I stand corrected. I went to Cameron, La. today about 250 miles from here and was amazed at what I found. Unloaded there, no tail wind, 70 mph cruise 16.71 mpg! Way better then 12.75 mpg. Loaded on the way back with this 5500 lbs dive chamber on my back I got 14.08 mpg at 65mph cruise.

All this with the 125 hp can tune and just removing the square headache rack.

I wondering how much more is possible once I take the liftgate off?