Question for you Ford 6.0 PSD

wingfoot · Sep 6, 2011

I have a 2005 Ford F250 6.0 PSD...I am pulling a 3400RE Bighorn..My question is, do you pull in "Tow Haul" while cruising at Interstate speeds. I found out on a recent trip over the same highways, coming home I got 9.4 MPG in tow haul, and going I got 10.4 MPG pulling out of tow haul. It seems like I can do just fine out of tow haul. Plus, I increased my MPG by one full mile. I have boost, tranny, and EGT gauges and I noticed no significant difference pulling at highway speeds out of tow haul. I do switch to Tow Haul in cities though.

What do you guys do?

Larry

Jellystone · Sep 6, 2011

wingfoot, I do not have a Ford F250 but I do have a Dodge 3500 dually. I always use the Tow/Haul option when pulling heavy loads. The Tow/Haul feature is supposed to work with the transmission to ensure that proper gear selection is occuring.

My question to you is, what do you consider Interstate speeds? All of these weight carrying trailer tires are only rated for 60mph speeds. Anything over 60mph can weaken/damage tires that would cause them to fail. I see a lot of folks flying down the Interstate at speeds greater than 60mph while pulling these heavy campers and coincidently I see a lot of posts about tire blowouts. ---Things that make you go, hmmmm!

My advice to you would be to use the Tow/Haul button when towing. Also, keep it at 60mph or less when towing that Bighorn.

wingfoot · Sep 6, 2011

Jellystone said:
wingfoot, I do not have a Ford F250 but I do have a Dodge 3500 dually. I always use the Tow/Haul option when pulling heavy loads. The Tow/Haul feature is supposed to work with the transmission to ensure that proper gear selection is occuring.

My question to you is, what do you consider Interstate speeds? All of these weight carrying trailer tires are only rated for 60mph speeds. Anything over 60mph can weaken/damage tires that would cause them to fail. I see a lot of folks flying down the Interstate at speeds greater than 60mph while pulling these heavy campers and coincidently I see a lot of posts about tire blowouts. ---Things that make you go, hmmmm!

My advice to you would be to use the Tow/Haul button when towing. Also, keep it at 60mph or less when towing that Bighorn.

Thanks for your response. About 60 to 65 MPH is my comfort zone. Also, I believe if you check, you will find that all ST/trailer tires are rated for 65 MPH max...

Click to enlarge.

TXBobcat · Sep 6, 2011

I have a 2006 F250 6.0 Diesel and HL 3400RE. I talked to my Ford transmission mechanic and he told me to always tow in T/H. Keeps the transmission oil moving and cooler. Once you get above about 58/59 the transmission will shift into overdrive but you will still have the T/H function available. I try to tow on interstates, that are not a wreck, at about 63mph, but I do try to keep the speed above 58. This keeps it in 5th gear overdrive. You have a 5th gear and a 5th gear overdrive. I had a set of Edge Gages, installed and I can see which gear I am running in and it helps a lot.

BC

brianharrison · Sep 6, 2011

Currently have the 6.4L, but last truck was the 6.0L PSD. I always use tow/haul when towing.

You are well ahead with measurement of EGT, tranny temps so you are in the best position to know where your truck likes to pull.

As mentioned the tow/haul alters the tranny shift points to ensure tranny fluid is circulating at max possible rates to cool tranny and keep fluid pressures up in the tranny to to reduce wear.

You probably also know it keeps the rpms up on the decel to use engine braking to assist deceleration and reduce brake system over use on hill decents.

Hope this helps,

Take care,
Brian

wingfoot · Sep 6, 2011

Thanks guys for the input...I've only got 102,000 miles on my truck and bought it new...so you would think I'd have learned by now..When pulling my previous Holiday Rambler 30 footer my truck seemed to engage OD much sooner...but this 5r is heaver by a couple thousand pounds...just trying to get little better fuel mileage..as stated it's dropped about one-mile per gallon...but I guess it should with the extra weight..

rustyshakelford · Sep 7, 2011

Is it possible you had a tailwind going and bucked a headwind coming home? That could easily account for 1mpg difference

Brett

Grdsman · Sep 7, 2011

I like the fact that the tow/haul mode downshifts when going downhill, but does it bother anyone when it does it to the point that the engine is revving at 3800-4000 RPM? It bothers me....

Also, I can't seem to go up Wilkerson Pass at greater than 45-50 MPH, which is a 5.8% grade, with a 14K load. Is this normal? Other trucks seem to pull the hill easier.

Jellystone · Sep 7, 2011

That sounds good. I always like to keep it around 55mph-60mph max, with cold tire pressure at the max rating listed on the tire itself. I've read a bunch of articles from "RV Experts" saying not to exceed 60mph in order to prevent possible tire problems.

wingfoot said:
Thanks for your response. About 60 to 65 MPH is my comfort zone. Also, I believe if you check, you will find that all ST/trailer tires are rated for 65 MPH max...

View attachment 15805Click to enlarge.

TXBobcat · Sep 7, 2011

Grdsman said:
I like the fact that the tow/haul mode downshifts when going downhill, but does it bother anyone when it does it to the point that the engine is revving at 3800-4000 RPM? It bothers me....
Also, I can't seem to go up Wilkerson Pass at greater than 45-50 MPH, which is a 5.8% grade, with a 14K load. Is this normal? Other trucks seem to pull the hill easier.

When you're going down hill and the engine gets up to about 3000 RPM, press on the brake peddle until the RPM's get down to about 2250 then let off and let it get back up to about 3000 and slow down to the 2250 RPM's again. Unless you have an engine brake you will have to do this. The newer trucks have an engine brake that will hold the truck close to a constant speed going down a mountain.

My 2006 F250 6.0 diesel 3.73 will pull up the 8% grade on I-90 going northwest from Butte MT and I got down to 39mph. I had a set of Edge Evolution digital gages installed on my truck. This has been a great help. I can view the Temp for the Exaust, Oil, engine coolant, transmission and what gear the transmission is using. When I went up the 8% grade my exaust temp was about 1200, my Engine coolant 220, Oil 230, transmission, 186. I tried to keep the engine RPM's to around 2500 and went down to 3rd gear. I was able to feather the throttle to maintain my speed and temps. I have 132,000 miles on my truck.
I hope this helps give you some idea of what to compare to your truck and trailer.

BC

wingfoot · Sep 7, 2011

Thanks BC, appreciate the input..

Grdsman · Sep 8, 2011

TXBobcat said:
When you're going down hill and the engine gets up to about 3000 RPM, press on the brake peddle until the RPM's get down to about 2250 then let off and let it get back up to about 3000 and slow down to the 2250 RPM's again. Unless you have an engine brake you will have to do this. The newer trucks have an engine brake that will hold the truck close to a constant speed going down a mountain.

My 2006 F250 6.0 diesel 3.73 will pull up the 8% grade on I-90 going northwest from Butte MT and I got down to 39mph. I had a set of Edge Evolution digital gages installed on my truck. This has been a great help. I can view the Temp for the Exaust, Oil, engine coolant, transmission and what gear the transmission is using. When I went up the 8% grade my exaust temp was about 1200, my Engine coolant 220, Oil 230, transmission, 186. I tried to keep the engine RPM's to around 2500 and went down to 3rd gear. I was able to feather the throttle to maintain my speed and temps. I have 132,000 miles on my truck.
I hope this helps give you some idea of what to compare to your truck and trailer.

BC

That's great info! Thanks! I already told my wife that I will have an Edge Insight CTS with EGT probe before the next trip.

lwmcguir · Sep 9, 2011

We no longer have any 6.0's but it might be worth mentioning again for those who missed all the post about the coolant. Keep it changed at 50k and it isnt a bad idea to install a coolant filter. Other than that we had good luck with them.

BHEWITTJR · Sep 10, 2011

I have the same set up only my truck is a 2006, and have noticed the same mileage differance. It is the result of being in tow mode the transmission stays in one gear longer to keep the load on the engine moving along, keeping momentium so the engine won't lag when shifting into a higher gear. When it lags the trans has to shift back down to a lower gear, and it will keep going up and down especially climbing a hill. That's when the fluid gets overheated and we all know the dangers of that. Then there is the advantage of keeping the converter locked up when stoping. I know on my truck it a big help stoping so the brakes don't get heated. When I'm on a mostly flat interstate I'll keep it turned off and the mileage will go up. I hope this helps you to understand a little better and enjoy your BH.

w

Grdsman · Oct 5, 2011

TXBobcat said:
When you're going down hill and the engine gets up to about 3000 RPM, press on the brake peddle until the RPM's get down to about 2250 then let off and let it get back up to about 3000 and slow down to the 2250 RPM's again. Unless you have an engine brake you will have to do this. The newer trucks have an engine brake that will hold the truck close to a constant speed going down a mountain.

My 2006 F250 6.0 diesel 3.73 will pull up the 8% grade on I-90 going northwest from Butte MT and I got down to 39mph. I had a set of Edge Evolution digital gages installed on my truck. This has been a great help. I can view the Temp for the Exaust, Oil, engine coolant, transmission and what gear the transmission is using. When I went up the 8% grade my exaust temp was about 1200, my Engine coolant 220, Oil 230, transmission, 186. I tried to keep the engine RPM's to around 2500 and went down to 3rd gear. I was able to feather the throttle to maintain my speed and temps. I have 132,000 miles on my truck.
I hope this helps give you some idea of what to compare to your truck and trailer.

BC

I just installed the Edge Insight CTS with the EGT Probe, changed the tranny fluid, engine oil and put new tires on the Cyclone.....I'm ready for hunting season! I didn't realize before having the Edge that the torque converter locks up in 4th gear, as well, when in Tow/Haul mode....that's good to know.

Question for you Ford 6.0 PSD

wingfoot

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Jellystone

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wingfoot

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TXBobcat

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brianharrison

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wingfoot

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rustyshakelford

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Grdsman

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Jellystone

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TXBobcat

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wingfoot

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Grdsman

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lwmcguir

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BHEWITTJR

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Grdsman

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