Mpg Towing

[packnheat]

I RECENTLY PULLED MY SNOWMOBILE TRAILER UP NORTH FOR THE WEEKEND. IT IS A V-NOSE - 15FT LONG BY 7 FOOT HIGH WEIGHS 2,500 LBS LOADED. MY AVERAGE SPEED WAS 74 MPH - 17LBS OF BOOST - 750 DEGREES EGT - IT WAS AROUND 12 DEGREES OUTSIDE. I GOT 12. 8 MPG GOING AND 10. 8MPG COMING HOME.



AM I EXPECTING TOO MUCH OR DOES THIS MILEAGE SUCK???





2002 QUAD CAB 4X4 2500 SHORTBED - 3. 55 GEARS - AUTO - EDGE EZ - GAUGES - 12,000 MILES

 

[baby.driver]

Sounds about right for an overvalved one.

 

[Desperado]

I get 17-19 mpg towwing a 20' by 8' 4,000 aluminum Weld Craft jet boat at 65mph, in the summer on summer fuel, winter fuel will get less mpg, from what I understand, I know my mpg's fall off in the winter a bit.

 

[klenger]

Towing that light you should be getting much better. I got about 14 pulling my old 21' 4000 lb TT. I get 10 - 11 with the 5er (10K).

 

[Cowboy Medic]

pulled my girlfriends car, a 2001 subaru legacy, on a flat bed trailer home at christmas and got 16 mpg going 65-70 mph. That was going across South Dakota. Wind was nominal and weather was decent, temps about 18 degrees. I would think you should be doing better, last summer I had some problems and felt like I was getting real bad milage, cleaned the IAT sensor and also found a loose clamp on the hose running out of the turbo to the cooler, after I did those two things I was back where I was used to.

 

[Ray Torresdal]

BOOST/EGT

17 lbs. boost, and only 750 egt doesn't jive, unless your pyrometer is post-turbo. If you were at 17 lbs of boost, that milage is about on. If pre-turbo egt's were 750, your milage should be much better. Ray

 

[RustyJC]

Re: BOOST/EGT

Originally posted by Ray Torresdal

17 lbs. boost, and only 750 egt doesn't jive, unless your pyrometer is post-turbo

When towing our 5ver, I've seen 850 degF pre-turbo EGT with 20-22 PSIG boost @ 70 MPH (mild headwind) and 700 degF with 12 PSIG boost @ 60 MPH - same 5ver, same day. What's so abnormal about 750 degF @ 17 PSIG boost IF a truck is modified like mine (i. e. , EZ with boost elbow, BHAF, 4" exhaust)? At WFO, I see 1100 degF max pre-turbo EGT @ 32 PSIG boost - yes, the truck is overaired. Some DD2's (along with a CON O-FE) will fix that!



Rusty

 

[Ray Torresdal]

gauge readings

When I'm running 20 psi boost, I'm in the 900 degree range - with VA box, boost elbow, and BHAF. When I'm sub 700 degrees, I'm seeing 19+ mpg, and minimal boost. I don't have the 4" exhaust, or injectors, but am surprised that you can run that much boost, and that cool. There is some possibility that gauge calibration isn't dead on, also.



Ray

 

[RustyJC]

Re: gauge readings

Originally posted by Ray Torresdal

There is some possibility that gauge calibration isn't dead on, also.

Ray,



Since I had my gauges on when my truck was completely stock, and since I saw 1300 degF pre-turbo EGT @ 22 PSIG max boost when towing in stock configuration, I don't think gauge calibration is an issue. My stock numbers are spot-on for a 2002 HO. The weekend I installed my EZ (with boost elbow) and 4" exhaust, I saw boost when towing increase from 22 PSIG to 32 PSIG and EGTs drop from 1300 degF to 1100 degF with just these changes.



Rusty

 

[packnheat]

MY EGT GAUGE IS MOUNTED PRE-TURBO. OTHER THAN CLEANING MY IAT SENSOR AND CHECKING MY HOSES. ANY OTHER POSSIBILITIES FOR POOR MILEAGE??

 

[Gary - K7GLD]

We commonly get between 16 and 17 mpg towing this setup in mixed valley/Sierra driving:

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The packed trailer adds about 7000 lbs to the truck, and I hold speed at 60-65 mph, in the flats or up the grades, and have the Comp on 5x5 when towing. Boost will max out at 32 psi in the grades, EGT stays around 1200 degrees max in those grades.



That fuel mileage is identical to what we got over the same route, same trailer, with our undervalved '91 with lots of Banks add-ons and tweaked pump - the new properly valved truck just does it far easier and with lots more comfort...

 

[AKDrifter]

winter towing 4,000 lbs.

winter fuel

camper on back

up and down big hills

50-65 MPH

14 MPG , in summer unloaded, 21 MPG

 

[Qualey]

I tow 13-14k, and with 4:10 gears and a 6 speed, I only get around 11-12 mpg. Heck, empty I only get around 14 at best! I think you should be getting better, but at least its not a gas motor!



Matt

 

[Steve M]

The front might be V shaped but the square back pulls a lot of suction at 74mph. Weight has less to do with it at 75mph. I get 10. 5 mpg towing our 5th wheel 65-68mph. I've gotten as high as 17mpg towing flat ground no wind 55mph but it's hard to stay awake. There's a huge difference in wind drag from 55 to 75mph.

 

[baby.driver]

Don't forget it ain't broke in yet either.

 

[Barry]

Baby Driver is right. 12,000 miles PLUS 12 degrees is not condusive to good fuel mileage. Give the truck a chance to break in and let it warm up a bit.

 

[DHawthorne]

This was posted on TDR some time ago relating to towing and mileage. You may not have seen it . It tells it real good. The

faster you go the less mileage your going to get . Load does not seem to be much of a factor. I hope this link works.



Its called "major towing report"



https://www.turbodieselregister.com/forums/showthread.php?threadid=24869

 

[Steve Campbell]

"The front might be V shaped but the square back pulls a lot of suction at 74mph."

..... sounds like a need for Air Tabs. They attach to the rear sides and top of the towed vehicle and "reduce" that drag/suction.

 

[Mpotter]

I get 9-12 mpg towing 10K, 21ft Wanderer Wagon. Depending on the wind. Stock configuration, 10300 miles on the OD. 20-22 running empty & no trailer. This is mountian/high desert towing & I'm very happy with the mpg. Just added the edge EZ, havn't towed with it yet. Mike

 

[Texas Diesel]

Drag increases to the square on the velocity (MPH), so double the MPH and the drag goes up 400%.



Someone correct me if I'm wrong.