2020 Ford F250 on 37s - Expedition Truck Camper Build!

[rruff]

But I want to bring more toys mostly dirtbikes/snowmobiles (w tools, fuel and gear) so not too heavy, but any slight hill or wind and the truck just falls flat, more so with the camper. Often times I lock it out of 6th/5th and still have to 'work' to keep 65 mph.

Horsepower is what gets you over the hill... 4th with stock gears will do just as well as 5th with a regear. Don't be shy about revving the engine! It's not hurting anything.

Modern trucks all have computer controlled throttle and shifting. I'd look into a way to customize those things before buying a regear. I think you have different selectable modes already with one being designed for towing and hauling.

 

[montypower]

@freelheeler

I doubt you'll find a re-gear worth the money. But that's just my guess! To find out... swap a set of stock tires onto the truck. That will be the equivalent ratio you'll get with 4.88 gears and 37s. 35s and 4.88s will give you a slightly lower ratio. Lower ratios will only really help on take off torque (1st gear) and 6th gear for essentially increasing the RPM. Downshifting essentially does the same thing the remainder of the time.

We towed for 2.5 months straight this year (just under 5k miles). Total combined weight was 16,000lbs. I think the truck did great.

My observations:

1. 6.2L likes "low rpm" it really chugs up hills... let it do it's thing. No need to romp it and rev like crazy. I'm amazed at what it will climb at 2k rpm or less. It is a torquey engine!

2. Using "Tow/Haul" mode is somewhat helpful (more responsive downshift). However, most of the time it is "overly aggressive" on engine braking (downhill) and I'll run in Manual mode. Often down hills I like to coast and enjoy the trailer push for a small MPG boost. But the truck will essentially deaccelerate in Tow/Haul on most hills.

3. Tuning. I've debated trying the "5 Star Tuning". This might be something worthwhile for you to try (for the money). I'm not a big fan of the transmission shift logic. It works alright but not brilliant. Our 2016 Tundra had much better tuning. This could help give you the "feel" you're looking for. I think the engine has plenty of power. Certainly more than nearly everything from the 90s and prior.

4. Steep grades. Peak power is around 4k RPM. That generally gets the job done and will hold speed or accelerate.

5. Economy. We have 55 gallons of fuel. Plus, we used an extra 5 gallons in the trailer to get enough range for cheaper Costco gas. Our fuel mileage: 7.9 (sustained 30 mph winds), 9.2, 10, 9.3, 9.3, 9.5, 9.1, 9.6, 9.0 - Not bad. Typically we are 10-12mpg without the trailer. Range is the biggest consideration for MPG.

6. Speed. This is HUGE!!! Slow down. We typically travel at 55-60mph. Rarely use cruise control. Pay attention to engine load more than maintaining an exact speed. Really got adjusted to slower travel after owning a Winnebago View (Mercedes Sprinter 3.0 Diesel) - it averaged 17mpg! It's much more relaxing going slower! Less stops will make a greater impact on travel distance than speed. Just be consistent and enjoy the journey.

7. Gears. We spend most of the time in 6th gear. I've found 5th gear to be rarely used or helpful. It's not really much lower than 6th and rarely is "enough" on steeper grades. 4th gear is the "pulling" gear and generally plenty for holding speed up hills. 3rd gear occasionally gets used on steepest hills or accelerating on grade. Slightly changing the transmission gear ratios would be helpful. I don't think 10 speeds is necessary but that is Fords solution. I'm not going to get onboard with that GM/Ford transmission until it has proven itself.

We love our Super Duty. It's reliable. And such a workhorse! Pulling the climb out of Vegas @ 110 degrees it stayed under 209 degrees (these modern trucks run hot - 198-200 thermostat) with COLD AC. And we're on 37s! Just got back to Arizona and dropped the camper and swapped for the dump trailer. Never misses a beat. No complaints. ScanGauge is a great investment to monitor your truck vitals.

You might consider a Hybrid or AT style tire. That will reduce the rolling resistance and possibly give you more of the feel you desire. Your truck can certainly handle the work duty. Relax. There's no reason to race hills at 70+ mph.

 

[RAM5500 CAMPERTHING]

Just found this build thread, hello and thanks! I've been around the site and under trucks for awhile and have recently been happy using what i got... however I seem to frequent this forum when i'm struggling w my setup and would like to hear more about towing using a 6.2 w camper, tire size 35 vs 37, re gearing vs different truck.

2019 F250 SC, 8' bed, 6.2 w 4.3 gearing, 6 spd tranny, 35" (Toyo MT's), Bilstein 5100s and airbags
2008 FWC Granby

I ordered the truck new and have put on nearly 50k (95% w the camper), I've crawled it around the mountains of MT, and taken it on extended overland adventures. Often times with a dirt bike in the hitch rack... it mostly just works. Than i bought a 2022 14' enclosed tandem axle trailer and that's when I started to think do i need more engine or different gearing, prior to more towing the rig did well 4.3 gearing and 35's. But I want to bring more toys mostly dirtbikes/snowmobiles (w tools, fuel and gear) so not too heavy, but any slight hill or wind and the truck just falls flat, more so with the camper. Often times I lock it out of 6th/5th and still have to 'work' to keep 65 mph. I know its not a diesel but.. I've pulled the trailer w a dodge cummings and u set the cruise at 80 and go.

I also need new tires and have been researching gearing for 37s... that said I don't like the idea of going away from the stock 4.3s so thinking a 'thinner' 35" but not convinced it'll make any difference. So back to gearing, would 4.88 or 5.(something) improve the overall performance using 35s? MPG is always a factor but this is not a daily driver, so i think I'm ok getn a little less.

My track record has been to buy more truck than I think I need... than good or bad a few years in i tend to grow out of it... the current super duty w 6.2 is awesome but i kind of want the new 7.3 or 6.7 diesel w the 10 spd tranny. I also have a budget and like my truck so if $2500 to re gear gets me 10-15% more and slightly better towing experience i'd be happy... i think.

For as much as re-gearing costs, moving from 4.30 to 4.88 would have such a little change/effect, it'd be hard to justify all the work and costs.

Its apples to oranges, but when i re-geared my Tundra (on 35s) from 4.30 to 5.29s, the tranny shifted a lot better, i got about 1mpg better, but that was about it.

For the cost of around $3000 or so for the regear, if i was in the same boat all over again, i wouldn't of bothered, and i would of just gone down to 33s.

My .02

 

[rruff]

I just looked up the ratios and the gearbox on the F250 is already 20-25% lower geared than the Tundra, when both have the same 4.3 final ratio. The Tundra with 5.29 is very comparable to the F250 with 4.3.

​	​	​	​	​	​	​	​
​	Tundra​	4.3​	5.29​	​	​	F250 (6)​	4.3​
​	​	​	​	​	​	​	​
1​	3.333​	14.332​	17.632​	​	​	4.170​	17.931​
2​	1.960​	8.428​	10.368​	​	​	2.340​	10.062​
3​	1.353​	5.818​	7.157​	​	​	1.520​	6.536​
4​	1.000​	4.300​	5.290​	​	​	1.140​	4.902​
5​	0.728​	3.130​	3.851​	​	​	0.870​	3.741​
6​	0.588​	2.528​	3.111​	​	​	0.690​	2.967​

I have 35s on mine and a level; stock gears. Average over 17 mpg, and it shifts and drives fine. Not hauling a load yet though...

I wouldn't recommend going to smaller tires as a solution for anything. Bigger tires are better offroad, plus better ground clearance, and actually have lower rolling resistance all else being equal. The drive ratio change of going from 35s to 37s is only 6%, vs 23% going from 4.3 to 5.29.

Unfortunately the rolling resistance of truck tires is all over the place, and no one tests it. I know my Hankook ATMs are excellent in this respect (better than the stock street tires), but most ATs will be a significant hit, and MTs even worse. I doubt the differences will be felt so much, though.

 

[mk216v]

I still need lots more miles on my '19 F350 6.2L with 4.88s and 37"s, but I have been finding myself perfectly happy cruising the highway at 55-65mph, no need to go faster (other lighter vehicles are for bombing at 80mph to Utah).

Interesting to hear your "low rpm" feedback Peter(montypower), I find that my truck will still pull a slight grade in 6th, but the engine is lugging and I'm personally not a fan. So if I need I just hit the +/- on the column shifter and shift down to 5th to get the rpms up and the truck seems to move along easier then.

I've thought about a 5Star tune as well with different modes, but trying to stay with KISS as long as possible.

Will advise on MPG with my setup as time goes on. Like Peter, I chose the 6.2L/6spd as a less complicated/proven/reliable setup. Sure, thrust from a big 6.7LTD would be fun for a few seconds, but knowing what I know about this industry and modern TD's, no thx; I'll arrive 30min later in my gasser.

 

[montypower]

Interesting to hear your "low rpm" feedback Peter(montypower), I find that my truck will still pull a slight grade in 6th, but the engine is lugging and I'm personally not a fan. So if I need I just hit the +/- on the column shifter and shift down to 5th to get the rpms up and the truck seems to move along easier then.

Try monitoring the real time fuel consumption / MPG. It definitely likes the low rpm. Shifting to 5th will typically drop fuel economy 2mpg. It's amazing the hills the motor will pull at 2k rpm or less. Around town it seems to stay under 1,500rpm. Worth playing with for sure!

Towing mode makes the downshift much quicker. In Normal mode it will drop speed a ton before downshifting (annoying). We dropped our camper and unloaded the trailer. It felt like a rocket driving with an empty trailer. HAHA

I did notice... keeping somewhat close in axle ratio to factory is helpful for pulling grades. 4th Gear is just under 3k rpm @ 60 (which is generally plenty). 3rd gear is just under 4k rpm @ 60 (this gives max engine power). If you gear your truck too low (or too small of tires for gears) you'll be going slower at the peak power band... or your RPM will be over peak power band to maintain 60mph. Just food for thought.

 

[mk216v]

Try monitoring the real time fuel consumption / MPG. It definitely likes the low rpm. Shifting to 5th will typically drop fuel economy 2mpg. It's amazing the hills the motor will pull at 2k rpm or less. Around town it seems to stay under 1,500rpm. Worth playing with for sure!

Towing mode makes the downshift much quicker. In Normal mode it will drop speed a ton before downshifting (annoying). We dropped our camper and unloaded the trailer. It felt like a rocket driving with an empty trailer. HAHA

I did notice... keeping somewhat close in axle ratio to factory is helpful for pulling grades. 4th Gear is just under 3k rpm @ 60 (which is generally plenty). 3rd gear is just under 4k rpm @ 60 (this gives max engine power). If you gear your truck too low (or too small of tires for gears) you'll be going slower at the peak power band... or your RPM will be over peak power band to maintain 60mph. Just food for thought.

Definitely agree with Tow/Haul; downshifts very quickly when I need it to.

On my setup (4.88s and 37"), I'm seeing;
6th gear is 2000rpm at 60mph
5th gear is 2500rpm at 60mph
4th gear is 3400rpm at 60mph
Haven't checked 3rd gear at XXXXrpm at 60mph

 

[montypower]

Definitely agree with Tow/Haul; downshifts very quickly when I need it to.

On my setup (4.88s and 37"), I'm seeing;
6th gear is 2000rpm at 60mph
5th gear is 2500rpm at 60mph
4th gear is 3400rpm at 60mph
Haven't checked 3rd gear at XXXXrpm at 60mph

Have you used Forscan to re-program your gear ratio and tire size?

 

[mk216v]

Have you used Forscan to re-program your gear ratio and tire size?

Negative, haven't Forscan'd for 37" tires as I don't want a CEL perpetually on.
https://www.ford-trucks.com/forums/1649945-forscan-threads-and-resources-index.html

Have you?

 

[montypower]

Yes. No lights. Speedometer is dead on with 37s. Getting the tire size changed in the computer with the axle ratio will help computer with shifting. And correct mpg, speed and odometer.

There are lots of fun things that can be programmed. Window functions, display screen, lights and lots more. Neat for essentially free!

 

[mk216v]

Yes. No lights. Speedometer is dead on with 37s. Getting the tire size changed in the computer with the axle ratio will help computer with shifting. And correct mpg, speed and odometer.

There are lots of fun things that can be programmed. Window functions, display screen, lights and lots more. Neat for essentially free!

Interesting to no CEL, great to hear! I guess I'll have mine Forscan'd again (already have some of the fun things done, thx to some of your suggestions), and see if I get a CEL or not. Can always revert eh?

 

[montypower]

Interesting to no CEL, great to hear! I guess I'll have mine Forscan'd again (already have some of the fun things done, thx to some of your suggestions), and see if I get a CEL or not. Can always revert eh?

Yep. It's easy to change and test. There is a maximum tire diameter the computer will accept.

TIRE DIAMETER
ABA is listed as the "Tire Circ. Limit" which is 2746 (decimal) or 0xABA (hex) - 0ABA
PCM Update required after completing

TPMS Pressure Limits (change what air pressure light is triggered). Helpful with lower PSI tires.
BdyCM – module configuration
TPM – Placard Front (psi)
TPM – Placard Rear (psi)

There's lots of info online on other changes and how to.

 

[mk216v]

Yep. It's easy to change and test. There is a maximum tire diameter the computer will accept.

TIRE DIAMETER
ABA is listed as the "Tire Circ. Limit" which is 2746 (decimal) or 0xABA (hex) - 0ABA
PCM Update required after completing

TPMS Pressure Limits (change what air pressure light is triggered). Helpful with lower PSI tires.
BdyCM – module configuration
TPM – Placard Front (psi)
TPM – Placard Rear (psi)

There's lots of info online on other changes and how to.

Yep, linked above to the Google spreadsheet for anyone else.
I've already done the TPMS mod, just need to do the 37s mod now that I know the CEL may not actually stay on afterwards, thx!

 

[montypower]

In this series we travel OFF ROAD through the entire state of Idaho! Our track follows much of the BDR route (Back Country Discovery Route). However our track is altered to incorporate historic sites and plenty of recreational activities such as paddle boarding and mountain biking. We will spend a total of 6 weeks enjoying the Idaho backcountry.

You can download the Idaho BDR maps here: https://ridebdr.com/idbdr/

In this video we travel Section 7 starting in Clark Fork and heading south to Wallace. We primarily used Gaia Maps (offline).

Be sure to slow down, explore and enjoy the areas! There are many fire lookout towers and fun sites to discover along the way. This route was mapped for dual sport motorcycles and you’ll likely encounter many during the high summer travel season. However, most vehicles can make the journey as it is primarily forest service roads.

More to come…

 

[Betarocker]

FORScan has a patch to deal with the error when changing tire size.