Towing - Best gear ratio

[theblet]

On this topic bc i just got back from 750 miles trip picking up my new 8.5 x 20 EMPTY enclosed trailer, 7 foot tall, 3200#.

My truck is 2022 1500 Limited Longhorn, 5.7 e torque with 3.92 gears, 33 gallon. We towed 95 north, GA to MD, mostly flat but some hills for sure. Got 7 mpg. Very disappointed. Engine has plenty of power, but stuck in 5th, 6th most of the time, even level or downhill stretches, fuel tank empties less than 250 miles. Tried to stay at 70mph most times. Checked trailer hub temps every stop.... just warm, so all good there. Future trips will be to West VA, mostly mountains.

(My 2012 Nissan NV2500 with 5.6 V8 towing open trailer w car weighed 5000# and I got 10-12 mpg. Less windage I know.)

Curious what MPG is your hemi getting towing a TT or enclosed car trailer? Is 7 about right? Thinking i shouldve gotten 2500 with diesel bc my now empty trailer will gain about 2,000#'s shortly with quads, etc.

If it’s a heavy trailer with alot of wind resistance that’s gonna kill mpg. I got about 13 towing a 16ft tandem axel flat trailer with a few hundred pounds of steel on it.

 

[irishwake63]

On this topic bc i just got back from 750 miles trip picking up my new 8.5 x 20 EMPTY enclosed trailer, 7 foot tall, 3200#.

My truck is 2022 1500 Limited Longhorn, 5.7 e torque with 3.92 gears, 33 gallon. We towed 95 north, GA to MD, mostly flat but some hills for sure. Got 7 mpg. Very disappointed. Engine has plenty of power, but stuck in 5th, 6th most of the time, even level or downhill stretches, fuel tank empties less than 250 miles. Tried to stay at 70mph most times. Checked trailer hub temps every stop.... just warm, so all good there. Future trips will be to West VA, mostly mountains.

(My 2012 Nissan NV2500 with 5.6 V8 towing open trailer w car weighed 5000# and I got 10-12 mpg. Less windage I know.)

Curious what MPG is your hemi getting towing a TT or enclosed car trailer? Is 7 about right? Thinking i shouldve gotten 2500 with diesel bc my now empty trailer will gain about 2,000#'s shortly with quads, etc.

Ive got 11 mpg in my last 2 Rams and 1 21 F150 with the 2.7 not this one

 

[Wire4money]

On this topic bc i just got back from 750 miles trip picking up my new 8.5 x 20 EMPTY enclosed trailer, 7 foot tall, 3200#.

My truck is 2022 1500 Limited Longhorn, 5.7 e torque with 3.92 gears, 33 gallon. We towed 95 north, GA to MD, mostly flat but some hills for sure. Got 7 mpg. Very disappointed. Engine has plenty of power, but stuck in 5th, 6th most of the time, even level or downhill stretches, fuel tank empties less than 250 miles. Tried to stay at 70mph most times. Checked trailer hub temps every stop.... just warm, so all good there. Future trips will be to West VA, mostly mountains.

(My 2012 Nissan NV2500 with 5.6 V8 towing open trailer w car weighed 5000# and I got 10-12 mpg. Less windage I know.)

Curious what MPG is your hemi getting towing a TT or enclosed car trailer? Is 7 about right? Thinking i shouldve gotten 2500 with diesel bc my now empty trailer will gain about 2,000#'s shortly with quads, etc.

I have a Hemi/quad/4x4/3.92 and get 9-11 towing a 4000lb 9’ tall travel trailer. I tow between 60 and 70, but notice a drop the faster you go.

 

[Davidbt]

On this topic bc i just got back from 750 miles trip picking up my new 8.5 x 20 EMPTY enclosed trailer, 7 foot tall, 3200#.

My truck is 2022 1500 Limited Longhorn, 5.7 e torque with 3.92 gears, 33 gallon. We towed 95 north, GA to MD, mostly flat but some hills for sure. Got 7 mpg. Very disappointed. Engine has plenty of power, but stuck in 5th, 6th most of the time, even level or downhill stretches, fuel tank empties less than 250 miles. Tried to stay at 70mph most times. Checked trailer hub temps every stop.... just warm, so all good there. Future trips will be to West VA, mostly mountains.

(My 2012 Nissan NV2500 with 5.6 V8 towing open trailer w car weighed 5000# and I got 10-12 mpg. Less windage I know.)

Curious what MPG is your hemi getting towing a TT or enclosed car trailer? Is 7 about right? Thinking i shouldve gotten 2500 with diesel bc my now empty trailer will gain about 2,000#'s shortly with quads, etc.

We did a 3,500 mile trip in October from South East Arizona to Mississippi and then back up through North East New Mexico and then back home with a 26' travel trailer that weighs all of 5,500lbs. Averaged 11 mpg's through the trip.

 

[silver billet]

On this topic bc i just got back from 750 miles trip picking up my new 8.5 x 20 EMPTY enclosed trailer, 7 foot tall, 3200#.

My truck is 2022 1500 Limited Longhorn, 5.7 e torque with 3.92 gears, 33 gallon. We towed 95 north, GA to MD, mostly flat but some hills for sure. Got 7 mpg. Very disappointed. Engine has plenty of power, but stuck in 5th, 6th most of the time, even level or downhill stretches, fuel tank empties less than 250 miles. Tried to stay at 70mph most times. Checked trailer hub temps every stop.... just warm, so all good there. Future trips will be to West VA, mostly mountains.

(My 2012 Nissan NV2500 with 5.6 V8 towing open trailer w car weighed 5000# and I got 10-12 mpg. Less windage I know.)

Curious what MPG is your hemi getting towing a TT or enclosed car trailer? Is 7 about right? Thinking i shouldve gotten 2500 with diesel bc my now empty trailer will gain about 2,000#'s shortly with quads, etc.

You already got some good replies, my experience towing 6000 lbs with an 8ft wide TT trailer (not very long, but it's the frontal area + weight that matters most here): I get anywhere from 9 to 11 mpg keeping it around 63 to 65. I stay in 6th gear (using the gear limiter), but on flat land with no wind or a tail wind it will sit in 7th if I let it.

 

[Mr.Grid]

On this topic bc i just got back from 750 miles trip picking up my new 8.5 x 20 EMPTY enclosed trailer, 7 foot tall, 3200#.

My truck is 2022 1500 Limited Longhorn, 5.7 e torque with 3.92 gears, 33 gallon. We towed 95 north, GA to MD, mostly flat but some hills for sure. Got 7 mpg. Very disappointed. Engine has plenty of power, but stuck in 5th, 6th most of the time, even level or downhill stretches, fuel tank empties less than 250 miles. Tried to stay at 70mph most times. Checked trailer hub temps every stop.... just warm, so all good there. Future trips will be to West VA, mostly mountains.

(My 2012 Nissan NV2500 with 5.6 V8 towing open trailer w car weighed 5000# and I got 10-12 mpg. Less windage I know.)

Curious what MPG is your hemi getting towing a TT or enclosed car trailer? Is 7 about right? Thinking i shouldve gotten 2500 with diesel bc my now empty trailer will gain about 2,000#'s shortly with quads, etc.

I tow a 7k# 24’ -8.5’ enclosed car hauler through the Appalachians (Fancy Gap) from Ohio Hy-35 to NC I-77/74 Winston-Salem that is 4.5% grade and mileage will suffer on that stretch of roads. On more level roads, it’ll stay in 7th towing at 65-67mph. The difference from towing at 70 compared to 65 can be dramatic in reduced fuel mileage. Using cruise can help improve mileage when not towing inclines.

My first fuel stop (longest) from WI to NC is 292 miles just before Indianapolis at a Loves truck stop. I have always made this stop, even in stronger headwinds, never fueling more than 31.2 gallons at worst. Generally, 28 gallon range. I always carry 5 gallons of gas in the trailer in the event of not making my first stop. Never needed it using this 2022 Laramie with 3.92.

First Tow with 2022

 

[tech97elec]

Thanks for all the replies!

All of you got more than my 7mpg. I was at 70 ish mph most of time, maybe need 65mph due to wind resistance. I didnt reset AVERAGE MPG from driving south wo trailer. Sat at a miserable 7 mpg

 

[2021QCBH]

My 3.21/5.7 non E torque does great. Plenty of power but I never intend to tow anywhere near max trailer weight on this one. 3.92s would totally be necessary for high wind resistance type towing imo. With the older transmissions I wouldn’t have considered anything but at 3.92 but this truck gets excellent highway mpg unloaded. Pending wind/route/speed it will generally run between 20-24 mpg for a tank.

I have a question for the 3.92 guys, my truck locks out 8th when in tow haul. Does the ECM also lock 3.92 trucks out of 8th? My truck in 7th runs a pretty similar RPM to a 3.92 rig in 8th. Runs around 2k rpms which is perfect for it to hold gear on flats and most normal elevation change.

I generally tow 4000-4500 lbs and close to max payload when we travel. It’s a boat so low wind resistance compared to the camper guys and it returns anywhere from 11.5-13.5 mpg pending terrain/speed.

I’m generally not one to slow down when pulling steep grades but I watch temps and will slow down if there are safety concerns. This spring I pulled a (7% IIRC) that seemed to be several miles long at 65 mph and 2800-2900 rpms holding gear with the cruise on. Water and trans stayed normal but I ran the oil up to 255. I would have slowed down at that temp but I had just crested the hill when it hit that temp.

 

[Willwork4truck]

Air suspension, larger fuel tank, etc are must haves for me. I’ll be avoidin the pano and ram box as to achieve a payload on a limited or limited longhorn of 1300-1400lbs.

I don’t care too much about which is fast 0-60, if that was my priority I would be ordering a f-150 Hybrid. Yet, it sounds like the sentiment leans heavy towards the 3.92. The MPG might be less, but capability and potentially longevity of the powertrain might offset that.

I guess another way to think of it is this - it would be a shame to spend 74k+ on a truck that is hamstrung by the gear ratio.

Always think about resale. As much as we tend to think we are keeping this vehicle for 10+ years,we generally don’t.

3 new vehicles since spring 2019 for me. Dumb financially I know but each one was a “long term purchase” that got interrupted when “life happened”.

Like my screen handle says, “willwork4truck”. I likely will be working for a few years to come, partially for funds and partially cause I can‘t sit at home like some retired guys do. With no hobbies (well 8 grandkids and a wife who likes the beach may qualify) I will always need “that little bit extra”.

 

[Rick3478]

I have a question for the 3.92 guys, my truck locks out 8th when in tow haul. Does the ECM also lock 3.92 trucks out of 8th? My truck in 7th runs a pretty similar RPM to a 3.92 rig in 8th. Runs around 2k rpms which is perfect for it to hold gear on flats and most normal elevation change.

My BigHorn doesn't lock it out, but in Tow/Haul doesn't shift into 8 until you get up to around 70 MPH. And that's unloaded - with a trailer might be higher.

 

[2021QCBH]

I have witnessed mine tow in 8th for a bit but that only happens when I forgot to click on tow haul and am already at speed (IE turn on tow haul when I’m already lugging along in 8th). As soon as it needs to down shift it won’t go back into 8th again even when decelerating. I figured the 3.92 might use 8th since the rpm would be similar to my truck in 7th.

 

[Willwork4truck]

If it’s a heavy trailer with alot of wind resistance that’s gonna kill mpg. I got about 13 towing a 16ft tandem axel flat trailer with a few hundred pounds of steel on it.

All peeps need to realize that towing limits (the much ballyhooed gvwr numbers) are for a low height load on a car hauler type trailer with minimal “sail” factor. They are NOT the same as any TT or 5th wheel. The front and sidewall wind resistance is a “whole nuther’ factor to consider, not just “can my truck tow this trailer” questions.

I realize OP was talking about gearing. It’s my thought that anything that will help your drivetrain tow that brick down the road is better. That would favor “deeper” gears.

Back in the day 4.10’s were the typical towing ratio, of course we only had 3 and 4 speed automatic transmissions. Toyota had a 4.30, Ford went to a 4.30 with their V10’s etc.

Now if RAM had not dropped the 3.55’s with the hemi, that would have been a nice in-between choice. I had 3.55‘s on my 2015 F150 instead of the 3.73 or 4.10 and it did fine towing up to 7K as well as empty highway mpg driving. (Course the 2.7 ecoboost engine had plenty of power.)

 

[silver billet]

3.92s would totally be necessary for high wind resistance type towing imo.

That's a common misunderstanding. 3.92's would do nothing to help in high wind resistance towing. It just gets you off the line easier in a lower gear, that's it. Think of it like an additional granny gear, once you're out of that gear it does nothing to help beyond that point.

 

[Willwork4truck]

If deeper gears helped so many towers for high wind resistance folks would be getting the high 4’s or even 5’s if available. Course that would kill empty mpgs.

Another reason I favor 3.92 over 3.21 is the opportunity to go bigger on wheels/tires. You don't want to further reduce the 3.21 gearing down to 3.0x something just because you decided on 35’s and a lift.
My opinion anyway.

 

[tech97elec]

I tow a 7k# 24’ -8.5’ enclosed car hauler through the Appalachians (Fancy Gap) from Ohio Hy-35 to NC I-77/74 Winston-Salem that is 4.5% grade and mileage will suffer on that stretch of roads. On more level roads, it’ll stay in 7th towing at 65-67mph. The difference from towing at 70 compared to 65 can be dramatic in reduced fuel mileage. Using cruise can help improve mileage when not towing inclines.

My first fuel stop (longest) from WI to NC is 292 miles just before Indianapolis at a Loves truck stop. I have always made this stop, even in stronger headwinds, never fueling more than 31.2 gallons at worst. Generally, 28 gallon range. I always carry 5 gallons of gas in the trailer in the event of not making my first stop. Never needed it using this 2022 Laramie with 3.92.

First Tow with 2022

So if my math was correct you get about 9.4 mpg? Is that about what the truck computes? Tx

 

[Mr.Grid]

So if my math was correct you get about 9.4 mpg? Is that about what the truck computes? Tx

That 9.4 mpg towing is the worst I’ve experienced with this 2022 Hemi Ram towing that 292 mile stretch because of windy conditions. Always around 10+ mpg on that stretch towing 65-67 normally. I don’t follow the average mpg display but Do follow the DTE display and zero the trip odometer when the low fuel light turns on. I’ll get an “Unknown fuel alarm” 35 - 40 miles after zeroing the trip odometer while continuing the drive. Using this I’ve been able to gauge how much fuel is remaining.

When leaving for this 292 mile drive my first stop is 2 miles from the house at a gas station where I top it off as full as possible. I’m also driving around Milwaukee using the freeway and through Chicago tollway that has me slowed to 60 mph in a 55 for 30+ miles.

The 230 mi third leg of my East coast trip over the Appalachians is from Ohio HY35/ SR850 through WV to Virginia I-77 Exit 1 in Lambsburg. This is 4.5 - 5% grade at Fancy Gap maintaining 55 mph. The lesser grades towing 60- 65 mph. I’ve had the fuel light go on traveling this route South to North. This is my worst for mileage towing 7k# in the 8 -8.5 mpg range.

 

[tech97elec]

That 9.4 mpg towing is the worst I’ve experienced with this 2022 Hemi Ram towing that 292 mile stretch because of windy conditions. Always around 10+ mpg on that stretch towing 65-67 normally. I don’t follow the average mpg display but Do follow the DTE display and zero the trip odometer when the low fuel light turns on. I’ll get an “Unknown fuel alarm” 35 - 40 miles after zeroing the trip odometer while continuing the drive. Using this I’ve been able to gauge how much fuel is remaining.

When leaving for this 292 mile drive my first stop is 2 miles from the house at a gas station where I top it off as full as possible. I’m also driving around Milwaukee using the freeway and through Chicago tollway that has me slowed to 60 mph in a 55 for 30+ miles.

The 230 mi third leg of my East coast trip over the Appalachians is from Ohio HY35/ SR850 through WV to Virginia I-77 Exit 1 in Lambsburg. This is 4.5 - 5% grade at Fancy Gap maintaining 55 mph. The lesser grades towing 60- 65 mph. I’ve had the fuel light go on traveling this route South to North. This is my worst for mileage towing 7k# in the 8 -8.5 mpg range.

Thanks Grid for the detailed explanation.... that helps. Wtf my mileage was so horrendous on mostly level ground, not windy, i have no idea.

Truck runs fine normally wo tow and gets 18 to 19 mpg depending, better on summer fuel blends.

Im outfitting trailer now.... so, more weight. We will see how it does with 1500 more pounds in trailer next time. Tx for all the replies!

 

[Rammer470]

You already got some good replies, my experience towing 6000 lbs with an 8ft wide TT trailer (not very long, but it's the frontal area + weight that matters most here): I get anywhere from 9 to 11 mpg keeping it around 63 to 65. I stay in 6th gear (using the gear limiter), but on flat land with no wind or a tail wind it will sit in 7th if I let it.

Do you ever worry about the higher RPMs that it runs in when you pull up long, steady inclines? Mine seems to love to hang in 7th at around 3600 RPMs, which makes me think that I’m hurting the tranny. When towing at 6th gear with that set up you’ve got, may I ask what do your RPMs sit around. Also, do your temps stay at ok levels etc? Much appreciated in advance.

 

[silver billet]

Do you ever worry about the higher RPMs that it runs in when you pull up long, steady inclines? Mine seems to love to hang in 7th at around 3600 RPMs, which makes me think that I’m hurting the tranny. When towing at 6th gear with that set up you’ve got, may I ask what do your RPMs sit around. Also, do your temps stay at ok levels etc? Much appreciated in advance.

My trailer loves to pull in 6th gear, it will do 7th if I let it but only on flat roads without much wind and then there is no headroom left, almost any dip in the pedal requires a downshift. When I'm on the freeway in 6th gear, I'm at about 2200-ish RPMs. MPH will be in the 63 mph area. I'm too lazy to calculate exact values but that's the general ball park from my memory. The truck will do this all day every day, not a problem.

6th gear in our trucks is "direct" gear, this is the best gear to choose for the life of the transmission (best to avoid overdrive gears while towing larger loads). The vast majority of the time my truck sits in 6th because I use the gear limiter to prevent upshifting beyond that. Hills will drop to 5th, or 4th if needed, but 3600 RPMs up a hill (if that's what you're seeing) is not an issue at all, neither for the engine nor the transmission.

When I'm towing I've learned to slow down. Not just in top speed but also in getting up to speed. Even backing off the pedal lightly can change the demands on the truck so much that instead of spiking to 4300 RPMs it might only need 3500 RPMs. Well worth the time just letting the truck bite instead of forcing it to almost max power.

The difference between the 3.21 and the 3.92, is basically that if I'm towing in 6th, the 3.92 will be towing in 7th at almost identical RPMs. The math works so beautifully for these specific gear ratios, such that they are basically always running the same RPM at the same MPH, except the 3.92 will be one numerical gear ahead. However the final gear ratio used will be almost identical. The exceptions are first gears, and when the 3.21 is in 8th but that will never happen when towing any significant load.

I have no idea how you manage to be at 3600 RPMs in 7th gear. I think you got something wrong there. 3600 in 4th or 3rd makes more sense to me.

My temps are all ok now. I used to see high-ish oil temps but I'm running a 180 thermostat now and that gives me more headroom. My transmission temps always run cool, never seen them get anywhere close to hot.