97 Superduty Fuel Consumption - F-Series & SuperDuty Diesel Forums

JR Sparky · 09-12-2011, 07:43 PM

We have about 3,000 miles pulling a 16,000+# boat and trailer and the last trip I was able to get a decent estimate of 7 MPG.

This truck has the 5.13 rear end and a 5 speed manual tranny and the RPMS are close to 2500 at 57 MPH which I chose as a normal cruising speed.

My question is : does anyone make a 2 speed axle or gear box for this thing?
I seem to remeber back in the late 60s they sold gear boxes to the guys who had to drive to the drag strips and those cars were putiing out 500 + HP.

We are located in Central Florida and our longest pull to date has been 300 miles one way to the Keys so hills are not an issue. Maybe this something we just live with ????

Patrick Feeley · 09-12-2011, 10:43 PM

Gear Vendors is the one that come to mind. I don't think US Gear still sells theirs. Cheers!

DaveBen · 09-12-2011, 11:15 PM

Hey Patrick, How is the fire there? Is it getting contained?

Dave

BJS · 09-13-2011, 08:06 AM

gearvendors makes an auxiliary overdrive that'll require some modification of the driveshaft and set you back around 3k new.

mathematically you'll likely never recoup the cost of the initial investment

Here's a post I made a while back on the subject

If memory serves me right you can get a lower gear for the rear end (lower numerically) which will lower your RPM provided you have enough power to get your boat moving from a stop and up the boat launch ramp. I can't remember if you have a Dana 110 or 135.

JR Sparky · 09-13-2011, 09:46 AM

I don't know which rear end is on it and it is parked in the RV lot, not readily accessible. My fear with a taller ring gear would be pulling it up the ramps as I don't have 4 wheel drive and the boat is really heavy. This would require a locker or some type of limited slip which together would probably throw the cost near the Gear Vender option.
Hopefully diesel fuel prices will remain steady for a couple more years.

Thanks for your thoughts.

BIG JOE · 09-13-2011, 10:04 AM

How 'bout just keep'n yer Eyes & Ears open for a complete Rear-end, housing, axels and all.. like with 4:??'s in it ?

Dogman · 09-13-2011, 02:06 PM

Sparky,
I would look at a gear change. It's going to be the cheepest way out, are you 4 wheel drive or 2 wheel drive? I looked at gearvendor and I was looking 3500.00+ after everything was done drive it home.

Patrick Feeley · 09-13-2011, 03:02 PM

Dave, thanks for asking! They've got a handle on them now I think. We didn't have to evacuate in our area (Bear Valley Springs), only precautionary evacuation measures (meaning be ready to go). Cheers!

DaveBen · 09-13-2011, 03:24 PM

Good deal Patrick. Keep safe.

Dave

JR Sparky · 09-13-2011, 03:45 PM

My 97 Superduty is DRW 2 wheel drive, with a 5 speed manual tranny and 5.13 rear end.
Have not weighed the tongue weght but estimate 1,100 # +/-. There have been a few ramps where the wheels would try to spin in granny with only idle RPMS. The other wheel would grab and so far, we have not had to have anyone pull us up any ramps.
Tried to insert a picture of the rig and trailer but obviously I don't know how.

09-12-2011, 07:43 PM	#1
JR Sparky SDD Junior Member Join Date: Jun 2011 Location: Leesburg FL USA Posts: 28 Thanks: 24 Thanked 0 Times in 0 Posts View Photos By: JR Sparky	97 Superduty Fuel Consumption We have about 3,000 miles pulling a 16,000+# boat and trailer and the last trip I was able to get a decent estimate of 7 MPG. This truck has the 5.13 rear end and a 5 speed manual tranny and the RPMS are close to 2500 at 57 MPH which I chose as a normal cruising speed. My question is : does anyone make a 2 speed axle or gear box for this thing? I seem to remeber back in the late 60s they sold gear boxes to the guys who had to drive to the drag strips and those cars were putiing out 500 + HP. We are located in Central Florida and our longest pull to date has been 300 miles one way to the Keys so hills are not an issue. Maybe this something we just live with ????

09-12-2011, 10:43 PM	#2
Patrick Feeley SDD Member Join Date: Apr 2005 Location: Tehachapi, CA Posts: 346 Thanks: 0 Thanked 19 Times in 19 Posts	Gear Vendors is the one that come to mind. I don't think US Gear still sells theirs. Cheers! __________________ 1997 F250 SC 4x4 (CA model), E4OD, 4.10 LS, Relocated Block Heater Plug, Mostly Stock SOLD - 1994 F350 CC DRW 2WD, 5 Speed, SBC Con-O, Baldwin Filter, Tymar HPX Hose, DPPI DP, Bilsteins, $12 AIC, Coolant Filter, Explorer Overhead Console, A-Pillar w/ISSPRO Black Ice, EV Boost, and EV Pyro, Modified Pedestal, Gutted EBPV.

09-12-2011, 11:15 PM	#3
DaveBen SDD Senior Member Join Date: May 2005 Location: Ukiah, California Posts: 7,869 Thanks: 127 Thanked 506 Times in 489 Posts	Hey Patrick, How is the fire there? Is it getting contained? Dave __________________ 2004 F-350 Regular cab with 6.0, Torqshift, 4X4, and just about all of the rest of the options. I added Guages, Satellite Radio, Air Horns, and a coolant filter. Bilstein shocks. Battery Desulphater that really works. Installed Jimmi Jammers. Pictures here: http://community.webshots.com/user/dbennett48 Completely Stock. I had a Detroit Diesel 8V92TA in a KW dump truck in 1980. That sucker would put out 425 hp but would never out pull a CAT.

09-13-2011, 08:06 AM	#4
BJS SDD Senior Member Join Date: Apr 2005 Location: Jacksonville, FL Posts: 1,498 Thanks: 4 Thanked 141 Times in 134 Posts	gearvendors makes an auxiliary overdrive that'll require some modification of the driveshaft and set you back around 3k new. mathematically you'll likely never recoup the cost of the initial investment Here's a post I made a while back on the subject If memory serves me right you can get a lower gear for the rear end (lower numerically) which will lower your RPM provided you have enough power to get your boat moving from a stop and up the boat launch ramp. I can't remember if you have a Dana 110 or 135. __________________ Brandon 95 F350 Centurion Conversion Bronco (Crew Cab SRW) 4X4 4.10, Isspro Performax Boost, Pyro, & trans temp on the A-pillar, BDP Stage 1 injectors, Open air intake, Dpp Downpipe, Self built E4OD with parts from Racer-X, Tony Wildman Chip, Early '99 Intercooler.

09-13-2011, 02:06 PM	#7
Dogman Dogman Join Date: Nov 2007 Location: tampa,FL Posts: 1,336 Thanks: 2 Thanked 104 Times in 90 Posts	Sparky, I would look at a gear change. It's going to be the cheepest way out, are you 4 wheel drive or 2 wheel drive? I looked at gearvendor and I was looking 3500.00+ after everything was done drive it home. __________________ 2008 F-250 All stock so far...LOL 1999 Jeep TJ play toy on 32" tires custom bumpers by me

09-13-2011, 09:46 AM	#5
JR Sparky SDD Junior Member Join Date: Jun 2011 Location: Leesburg FL USA Posts: 28 Thanks: 24 Thanked 0 Times in 0 Posts View Photos By: JR Sparky	I don't know which rear end is on it and it is parked in the RV lot, not readily accessible. My fear with a taller ring gear would be pulling it up the ramps as I don't have 4 wheel drive and the boat is really heavy. This would require a locker or some type of limited slip which together would probably throw the cost near the Gear Vender option. Hopefully diesel fuel prices will remain steady for a couple more years. Thanks for your thoughts.

09-13-2011, 10:04 AM	#6
BIG JOE SDD Senior Member Join Date: Apr 2005 Location: CenCal Posts: 4,377 Thanks: 101 Thanked 392 Times in 381 Posts	How 'bout just keep'n yer Eyes & Ears open for a complete Rear-end, housing, axels and all.. like with 4:??'s in it ?

09-13-2011, 03:02 PM	#8
Patrick Feeley SDD Member Join Date: Apr 2005 Location: Tehachapi, CA Posts: 346 Thanks: 0 Thanked 19 Times in 19 Posts	Dave, thanks for asking! They've got a handle on them now I think. We didn't have to evacuate in our area (Bear Valley Springs), only precautionary evacuation measures (meaning be ready to go). Cheers! __________________ 1997 F250 SC 4x4 (CA model), E4OD, 4.10 LS, Relocated Block Heater Plug, Mostly Stock SOLD - 1994 F350 CC DRW 2WD, 5 Speed, SBC Con-O, Baldwin Filter, Tymar HPX Hose, DPPI DP, Bilsteins, $12 AIC, Coolant Filter, Explorer Overhead Console, A-Pillar w/ISSPRO Black Ice, EV Boost, and EV Pyro, Modified Pedestal, Gutted EBPV.

09-13-2011, 03:24 PM	#9
DaveBen SDD Senior Member Join Date: May 2005 Location: Ukiah, California Posts: 7,869 Thanks: 127 Thanked 506 Times in 489 Posts	Good deal Patrick. Keep safe. Dave __________________ 2004 F-350 Regular cab with 6.0, Torqshift, 4X4, and just about all of the rest of the options. I added Guages, Satellite Radio, Air Horns, and a coolant filter. Bilstein shocks. Battery Desulphater that really works. Installed Jimmi Jammers. Pictures here: http://community.webshots.com/user/dbennett48 Completely Stock. I had a Detroit Diesel 8V92TA in a KW dump truck in 1980. That sucker would put out 425 hp but would never out pull a CAT.

09-13-2011, 03:45 PM	#10
JR Sparky SDD Junior Member Join Date: Jun 2011 Location: Leesburg FL USA Posts: 28 Thanks: 24 Thanked 0 Times in 0 Posts View Photos By: JR Sparky	My 97 Superduty is DRW 2 wheel drive, with a 5 speed manual tranny and 5.13 rear end. Have not weighed the tongue weght but estimate 1,100 # +/-. There have been a few ramps where the wheels would try to spin in granny with only idle RPMS. The other wheel would grab and so far, we have not had to have anyone pull us up any ramps. Tried to insert a picture of the rig and trailer but obviously I don't know how.

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