jrstout89
Tehachapi, Ca
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I will be picking up a new 5ver that will gross out at 11,500lbs. I have never towed anything that heavy. The heaviest tow in the mountains has been my 6k boat.
My new TV will be a F250 with the V10. I always hear about compression braking with the deisels but my question is for people who tow with gas engines.
Can you downshift into lower gears with the gas engine to help keep the speed down. Is it any harder on the transmission of a gasser to do so?
I appreciate any info. Thanks
2010 Ford F250HD V10 4.10
2010 Jayco 30.5RLS
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jesterdog
Texas
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Yes, downshift to a lower gear. Is it tougher on the tranny? Not as tough as flying off the mountain road and crashing into the creek below...
2001 Excursion 3.73 geared V-10
2007 R-Vision Trail Lite 8311S
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coolbreeze01
Redding, Ca
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Absolutely use your gears to control downhill speed, even 1st gear as needed. Your engine and transmission are designed to be used. You do not want to experience brake fade.
Have fun.
2008 Dodge 3500 CTD LB SRW 4X4 6-Speed Auto
P3 Blue Ox Sway Pro
2007 Komfort 212
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Gale Hawkins
Murray, KY
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jrstout89 wrote:I will be picking up a new 5ver that will gross out at 11,500lbs. I have never towed anything that heavy. The heaviest tow in the mountains has been my 6k boat.
My new TV will be a F250 with the V10. I always hear about compression braking with the deisels but my question is for people who tow with gas engines.
Can you downshift into lower gears with the gas engine to help keep the speed down. Is it any harder on the transmission of a gasser to do so?
I appreciate any info. Thanks
We use 3rd a lot and 2nd some and 1st only really steep grades to help reduce brake use. Since it does not happen every day and is at low speeds I know of no harm to the transmission.
NOTE: If your computer will automatically upshift at red line to protect the engine make sure you brake enought to keep RPM's below that magic number to keep from loosing the engine braking effect.
When towing it is important that you have trailer brakes that can stop its own weight without help from the TV. Speed is a killer of many things. Watch the loaded trucks. They know to creep down the dangerous slopes.
Interstate grades typically are not a concern. 10-14% slopes are a different story and need some preplanning. You can always speed up going down a mountain but stopping can be a different story so start out slow when in doubt. Know your trailer brakes limits before you learn by exceeding them half way down a mountain.
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cathcartww
Stone Harbor, NJ
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Plan ahead. Get into the lower gear at the top of the hill, well before you start down the slope. If you get rolling too fast, it is much harder to get most transmissions to down shift. Depending on your set up, you may also be able to use your brake control to manually apply the trailer brakes only as needed to keep things under control.
Bill and Kate from Stone Harbor, NJ
w/ Sunny (the parti poodle) & Molson (the goldendoodle)
2005 Ford/Quigley 4x4 E-350 Chateau Super Duty Van with 6.0L Power Stroke Diesel ("Moby")
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Gale Hawkins
Murray, KY
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On this subject does one know if the braking effect of a gas engine is better at certain RPM range. For example if red line is 4500 with the engine breaking effect at 3500 be less, greater or the same as at 4500. I have never seen anything in print. Let us assume there is NO automatic upshift feature.
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svedspx
SoCal
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If you have a brake controller like the Prodigy, it wouldn't hurt to set the boost up a notch or two as well as downshifting to a lower gear. Braking on a steeper grade puts a lot weight on the front truck brakes.
2009 Jayco 28.5 RLS Super Light
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Yahooligan
Temecula, CA
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Gale Hawkins wrote:On this subject does one know if the braking effect of a gas engine is better at certain RPM range. For example if red line is 4500 with the engine breaking effect at 3500 be less, greater or the same as at 4500. I have never seen anything in print. Let us assume there is NO automatic upshift feature.
In my experience, engine braking seems to be fairly even across the RPMs. I don't recall accelerating noticeably faster while going downhill as the RPMs increase. Also, the effect of wind resistance can change things as well. As you slow down you have less wind resistance helping you slow, so there should become a point on a given hill where engine braking stops slowing you down and instead holds you at a steady speed.
As for diesels, they have much less engine braking ability compared to a gas engine due to the fact that diesels don't have a throttle plate, so on the intake stroke they have no vacuum to fight against and, due to this, they also suck in normal amounts of air. Any braking provided by the resistance of compressing the air is nullified by the force of that compressed air pressing down on the piston once it passes TDC. Diesels with an exhaust brake or true Jake brake (Which is not an exhaust brake) are a different story.
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Hogan & Clan
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hwybnb
Southern California
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Use a combination of engine and friction braking, with most of it being done by the engine. As has been said think ahead. Downshift at the top of the grade before the speed starts to build. When you need to use the brakes get on them fairly hard for five to ten seconds and then get off to let them cool. If you find that you need to do that more than twice in a minute shift to a lower gear.
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othertonka
Stockton, CA
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Here is a suggestion to figure out which gear you should be in going down a hill. Take a piece of paper and pencil to record your findings.
#1 Determine your red line by looking in your owners manual, say for example it is 4500 RPM's. You need to get some baseline readings and that is what we are doing
#2 put your truck in first gear and accelerate until you reach 4300 RPM's, record the MPH's, In my case on a chev 8.1 with a 5 speed allison, it is 25 MPH at 4200 RPM's
#3 shift into 2nd gear and take it up to 4300 RPM's and record the MPH, in my case it is about 45 MPH at 4200 RPM's.
#4, put it in 3rd gear and do the same, up to 4300 RPM's and record your MPH, in my case it is 56 MPH at 4200 RPM's Now yours will be different depending on what tranny you have, I have a 5 speed allison, yours will be diffferent but the method is the same. Now make your self a DYMO lable with these figures and place it on your dash. Now when going down a hill, you can look at your speed, and if it is say below what your reading for 1st gear is, that you should be in 1st gear. In my case if I am coming down a 10 % grade and I want to keep it below 25 MPH, I down shift to 1 st gear at the top of the hill and when the RPM's reach 4200, I hit the brakes and bring the rpm's down to about 3500 and then release the brakes and let the RPM's climb again to 4200 and do the whole braking processs again, Use the same method for all other gears, this is will keep form overheating the brakes as they will cool when you let off for a while. If I am going between 25 and 45, I shift to 2nd, between 45 and below 56, I down shift to 3rd. By having the figures right on the dash, I know if I am below, say 56, I can safely down shift to 3rd without overreving the engine. Most modern transmissions will not let the downshift take place if it will end up overreving the engine, but with my method, I manually take control of the downshifts knowing in my mind I will not be overreving with my downshift.
Othertonka
2004 Southwind 32VS 8.1 Workhorse chassis
2002 CRV Toad
U. S. Gear Unified brake system
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