Hey all Got a 2001 4x4 TCD 5.9 auto 3.55" with new injection pump and airdog and BHAF and hypertech chip. Getting 17 mpg around townGetting 19 mpg on long haul interstateBut only get around 10 mpg towing 5000 lb 5th wheel. Any one got advice on how to get my towing experience and numbers up :O) Curious in your own numbers and weights. thx

Ok... Here I'm loaded with nearly 3 cords of firewood... My lowest MPG is 14 MPG ever on reocrd. As for weight... (empty)Total Weight 7,300# = 4,440# Front Axle + 2,860# Rear AxleI'm running a Edge Comp on 5x5 and keep my boost below 5 PSI anf pyro under 600*F and I see 20+ MPG empty. But towing the only advise is to set your cruise at 55 MPh and leave it alone...

Hi MichaelYeah - you mentioned that before - thx for the info - but was curious as what other people had experience with as that is a lot better than what I get towing. So was wondering what could cause my drop in mpg towing specifically - and if its normal - based on your figures it seems mine is a little low.So then I was wondering if I should drop my Hypertech and get a Edge like you ? Assuming yours is the 'Edge Products Comp Module' not the 'Edge EZ'. still working out if the hypertech is helping me - it feels better but last time I filled up the lie-o-meter said 20 (improved from 17) but the hand calc was 15.9. [Not towing]

Its been my experience that if I am doing a lot of towing when it is alot of stop and go I just forget about my MPG's. With an auto, I nurse it along and let the tranny work thru the gears rather than use my foot and motor right thru the gears. But, like Mike says, once you get up there just set it to cruise and let it rip. Last time I towed I was getting about 14 MPG's and then was going thru a lot of mountains and elevation changes.

hey gasser :P What weight you hitting 14 MPG towing ? any idea ? thx

I've not really towed enough lately to record MPG... but my 4:10 geared truck with OEM rubber is not real good on fuel. I'd have done better with standard ratio... HOWEVER, I have found that my automatic/OD truck does better if I use the right foot for speed control... and pay close attention to the road. I use the autopilot to give me short rests only. Speed is the #1 MPG killer. I do measurably better if I keep the speed around 55. My best ever MPGs running light, was on secondary routes where I got the automatic to shift into high and just stayed off the thottle... speed was about 40-45. The truck was just loafing, lugging a few small bumps (not even really hills) without down shift or turbo whistle. (I don't have a boost guage.) Back to the highway... Highway is all about windage & the faster you go the more airodynamics hurt you. I got rid of my 5th wheel before I took my Chevy gas C30 off the road... I never put that hitch into the CTD. My gooseneck horse trailer has a narrowed front so is less of a drag than the camper. Now when I'm trying to get MPGs, I let the truck coast where ever possible. My theory is holding the throttle steady at anything above idle takes more fuel than idle does. I try to keep my speed at what ever I've decided to so if it coasts down below that, I bump it back up & back off the throttle again on those down hill grades on the interstate. Going uphill, towing, I use the throttle & hold speed high enough to prevent downshifting. If I get caught in traffic, & have to down shift... I cuss a few times & spend the next mile getting the speed back up. I watch the speed on the crests of the hills (easier if I'm running light). I back off before the cruise would react, so I crest each hill with only the selected speed. Pretend their is a cop with an attitude running radar on the other side... Driving this way is tiring... because it is all manual. I like driving though... so that's some reward for the pain. I guess it would be better to run the cruise if you don't want the work of constantly watching every second. I made a few 6 hour interstate trips last year, running pretty light. One last thing, make sure your brakes are not dragging... I had a problem with this & found my MPG was horrible. Best wishes, Russ

Hi Michael Yeah - you mentioned that before - thx for the info - but was curious as what other people had experience with as that is a lot better than what I get towing. So was wondering what could cause my drop in mpg towing specifically - and if its normal - based on your figures it seems mine is a little low. So then I was wondering if I should drop my Hypertech and get a Edge like you ? Assuming yours is the 'Edge Products Comp Module' not the 'Edge EZ'. still working out if the hypertech is helping me - it feels better but last time I filled up the lie-o-meter said 20 (improved from 17) but the hand calc was 15.9. [Not towing]

Like here is a older PDF doc of my MPGs. http://mopar.mopar1973man.com/pdf/2002-dodge-fuel-records.pdf (Go to page 13 for the graph) I know I need to update this... Now take notice everything from start to 50K miles is completely stock, 50K to 90K is stock fuel, BHAF and Straight pipe, 90K Edge Comp was installed. By 120K I bought my ScanGauge II as a guide and BOOM! The numbers took off. But I've been hovering in the 20-21 bracket now empty. I do most of my trailer towing work in the summer. What worse about mine is I start from 2,800 ft and drive down to Lucile Idaho. Then turn up a single lane dirt road wind 6 miles to the saddle at 7-8% grade. Then head up the hill to about 7,800 ft to cut firewood. Then haul it back down. Even then going back though my notebook and Excel sheet the lowest is 14.30 MPG ever. Now as for Chip I found that a performance chip that ties t othe VP44 does the best for MPG because of the sole fact it can adjust timing farther than factory ECM limitations. Like it the morning getting rolling with a cold engine it rattles to beat all this is the advancement of timing. But if you just turn off the Edge Comp its gone. Or even un plug the wire tap it gone... The other thing I found is the rattle is completely gone after 7-10 PSI (timing canceled) So Edge EZ is not going to do more than ECM rate. Now as for setting I leave it on 5x5 (max'ed) and control the fuel with my foot just like the old days of 4 bbl carbs. I keep my boost low if possible (more boost means more fuel and less timing). Another thing that helped a bunch is the RV275 injectors. I gain about 1-2 MPG from those because of the change in spray pattern.

Edited February 14, 201015 yr by Mopar1973Man
Updated the PDF file and the page number.

Hey guys thanks - great info .......... haven't tried towing at 55mph - normally closer to 60-65 - so might look into that and see if any difference. crazy detail micheal - I do remember seeing that before - but quite useful right now I am focused more on MPG - where the heck do you get the time anyway - going to get a few more calcs with the BHAF/hypertech , and then probably consider new exhaustpossible switch to edge with vp44 taplater switch out for some lower weight tires might also consider injectors but 2 questions 1) I have auto stock transmission with 118k on clock and towing - could this be a bad move (too much torque/hp)2) Can I just do the 1st stage of injectors all all of them ?

Yeap that Auto is your weak link for getting the most out of your truck. If you did a Valve Body and TQ Conv at least it would hold the extra juice from a Chip and/or injectors. If your upgraded on the trans I would suggest trying a "Mystery Switch" for MPG's because then the Trans operates like a manual trans.

sweet any idea on approx cost "Valve Body and TQ Conv " and whats involved ? parts/labor ? can do basic stuff to my truck - but never played around with anything real mechanical on it or any other carhard to do ?

now that is a good question for the vendors of the site for a price... As for how to do it... Well the first person to mind is Wild & free could tell ya...

hey gasser :P What weight you hitting 14 MPG towing ? any idea ? thx

Don't really know. It was with a large U-Haul trailer when I moved from Southern Utah to Oregon. I only went about 55 the whole time and just let the tranny work up the speed though.

If your upgraded on the trans I would suggest trying a "Mystery Switch" for MPG's because then the Trans operates like a manual trans.

like a manual in 4th! i took my exhaust off this weekend because i was towing. i honestly don't know if it was the fuel or the exhaust...but even with pulling 120+ miles this is shaping up to be the highest mpg in my truck so far. the flying j's card reader was busted so i went to loves. their pumps said it contains 5%-20% bio. to my knowledge this is the first time my truck has had a bio blend. i will say that no muffler is LOUD!

Travel trailers are just hard on fuel. Its the windage. I can dip below 12 pretty easy with my 5K lb TT. I have a friend with an 02, Auto on 315's. He gets about 10-10.5 towing a TT or 5er. His TT is about 5K, his 5er was a 30' and he had an enclosed trailer behind it... Both got the same mileage. Windage kills, not weight.

Yeap that Auto is your weak link for getting the most out of your truck. If you did a Valve Body and TQ Conv at least it would hold the extra juice from a Chip and/or injectors. If your upgraded on the trans I would suggest trying a "Mystery Switch" for MPG's because then the Trans operates like a manual trans.

+1 on the switch. I've been using my truck for my daily commute to keep some of the miles off the car (also just plane love driving it =) ) 120miles daily. I've been palying around with the switch and i'm seeing about a .5 - .75 mpg improvement by using the switch as much as possible. Also using it to coast down saves the brakes a bit too. I will say that the winter diesel shure sucks though!

okSo installed a 4" SS TBE bullydog and edge juice with attitudeGot 2 MPG hand calculated:thumbup2: on 100 mile trip - was still rising slowly - so expecting 3 MPG on longer trip. No chance to test towing - but looks good so far Enjoying the power (when I want it) and the extra MPG when I need it - nice ! Will try and post a few more detailed fule records as time goes on comming months. thx moparman - who suggested these changes (as well as others)

My experience is with my truck and fiver. With the fiver and boat I am at 17,160#. The BIGGEST killer of fuel mileage while towing is frontal surface area. Weight does not seem to be much of a factor. The other thing is speed. At 70 MPH I get 10mpg at best, 65 MPH I get up to 12mpg, and have gotten 14+mpg at 60 MPH and under.

The BIGGEST killer of fuel mileage while towing is frontal surface area. Weight does not seem to be much of a factor.

I agree 100%, which is why 1/2 tons shouldn't be towing TT's, even if they only weigh 5K lbs.

I've not really towed enough lately to record MPG... but my 4:10 geared truck with OEM rubber is not real good on fuel. I'd have done better with standard ratio... HOWEVER, I have found that my automatic/OD truck does better if I use the right foot for speed control... and pay close attention to the road. I use the autopilot to give me short rests only. Speed is the #1 MPG killer. I do measurably better if I keep the speed around 55. My best ever MPGs running light, was on secondary routes where I got the automatic to shift into high and just stayed off the thottle... speed was about 40-45. The truck was just loafing, lugging a few small bumps (not even really hills) without down shift or turbo whistle. (I don't have a boost guage.)

Back to the highway... Highway is all about windage & the faster you go the more airodynamics hurt you. I got rid of my 5th wheel before I took my Chevy gas C30 off the road... I never put that hitch into the CTD. My gooseneck horse trailer has a narrowed front so is less of a drag than the camper. Now when I'm trying to get MPGs, I let the truck coast where ever possible. My theory is holding the throttle steady at anything above idle takes more fuel than idle does. I try to keep my speed at what ever I've decided to so if it coasts down below that, I bump it back up & back off the throttle again on those down hill grades on the interstate. Going uphill, towing, I use the throttle & hold speed high enough to prevent downshifting. If I get caught in traffic, & have to down shift... I cuss a few times & spend the next mile getting the speed back up. I watch the speed on the crests of the hills (easier if I'm running light). I back off before the cruise would react, so I crest each hill with only the selected speed. Pretend their is a cop with an attitude running radar on the other side...

Driving this way is tiring... because it is all manual. I like driving though... so that's some reward for the pain. I guess it would be better to run the cruise if you don't want the work of constantly watching every second. I made a few 6 hour interstate trips last year, running pretty light. One last thing, make sure your brakes are not dragging... I had a problem with this & found my MPG was horrible.

Best wishes, Russ

thank you for the nice write up!

---------- Post added at 12:51 PM ---------- Previous post was at 12:50 PM ----------

Like here is a older PDF doc of my MPGs.

http://mopar.mopar1973man.com/pdf/2002-dodge-fuel-records.pdf (Go to page 13 for the graph)

I know I need to update this...

Now take notice everything from start to 50K miles is completely stock, 50K to 90K is stock fuel, BHAF and Straight pipe, 90K Edge Comp was installed. By 120K I bought my ScanGauge II as a guide and BOOM! The numbers took off. But I've been hovering in the 20-21 bracket now empty. I do most of my trailer towing work in the summer.

What worse about mine is I start from 2,800 ft and drive down to Lucile Idaho. Then turn up a single lane dirt road wind 6 miles to the saddle at 7-8% grade. Then head up the hill to about 7,800 ft to cut firewood. Then haul it back down. Even then going back though my notebook and Excel sheet the lowest is 14.30 MPG ever.

Now as for Chip I found that a performance chip that ties t othe VP44 does the best for MPG because of the sole fact it can adjust timing farther than factory ECM limitations. Like it the morning getting rolling with a cold engine it rattles to beat all this is the advancement of timing. But if you just turn off the Edge Comp its gone. Or even un plug the wire tap it gone... The other thing I found is the rattle is completely gone after 7-10 PSI (timing canceled) So Edge EZ is not going to do more than ECM rate. Now as for setting I leave it on 5x5 (max'ed) and control the fuel with my foot just like the old days of 4 bbl carbs. I keep my boost low if possible (more boost means more fuel and less timing).

Another thing that helped a bunch is the RV275 injectors. I gain about 1-2 MPG from those because of the change in spray pattern.

Mopar you always have awesome informative write ups...thank you for your time and sharing your knowedge.

---------- Post added at 12:59 PM ---------- Previous post was at 12:51 PM ----------

ok

So installed a 4" SS TBE bullydog and edge juice with attitude

Got 2 MPG hand calculated:thumbup2: on 100 mile trip - was still rising slowly - so expecting 3 MPG on longer trip.

No chance to test towing - but looks good so far

Enjoying the power (when I want it) and the extra MPG when I need it - nice !

Will try and post a few more detailed fule records as time goes on comming months.

thx moparman - who suggested these changes (as well as others)

i like my edge juice w/att and run on 1x3 AND dont even have then pump tapped...well...i have a shealth cover plate when and if i decide to tapped the pump.make sure that you put her on a 2 cycle diet help out in the m.p.g's department alittle and your vp will will give you a