2020 Ford F250 on 37s - Expedition Truck Camper Build!
- Thread starter montypower
- Start date
montypower
Adventure Time!
I'm sure that an E or F tire would provide a much stiffer/stable tire for towing heavy. Mostly from increasing the tire pressure up 65-85lbs. Of course, online... you find people parroting things without researching or digging in. Overall just depends on the application and use.
I prefer a more compliant tire especially in rougher terrain.
I prefer a more compliant tire especially in rougher terrain.
rruff
Explorer
I think that is because the weight carrying has more to do with heat generation (which favors a large and flexible tire) than durability.
C, D, E, F etc is a ply rating is it not? So this would relate to tire stiffness, strength, and durability... or at least they should trend in that direction. As I mentioned earlier, higher ply rating tires *need* to run high pressure with a load because too much flexing will make them overheat.
It makes sense that a D tire will carry more load than a E at the same pressure, because the stiffer tire will generate more heat. The E will tend to be more durable and stable, but rougher riding due to the higher pressure requirement.
mk216v
Der Chef der Fahrzeuge
Not a ply rating any more. Info in my post here;
2020 Ford F250 on 37s - Expedition Truck Camper Build!
The weld on shock tabs we used are 1/4" thick. Fox uses the same hardware (nuts and bolts). So match factory hole size.
expeditionportal.com
Your two "overheat" sentences appear to contradict each other.
rruff
Explorer
It's a ply rating... just doesn't tell you what the load capacity is.
Per your link here: https://www.treadwright.com/blogs/treadwright-blog/understanding-tires-load-index-vs-load-range
"Load range simply tells how tough the tire is and the allowable PSI."
Where is the contradiction on overheating? The tougher tire will tend to generate more heat, all else being equal. You *need* to run them at higher psi (less tire flex) to keep them from overheating. But their ability to handle higher pressure allows them to carry a higher load. Unfortunately the "cost" tends to be a rough ride, and poor MPG. On the plus side the sidewalls should be more durable.
Peter's tires can carry a heavy load at low psi because they are large.... and probaly less "tough" (stiff) than an equivalent size tire with an 80psi rating. Tradeoffs.
mk216v
Der Chef der Fahrzeuge
Tire "toughness" (Load Range) is pretty damn subjective IMHO; how tough is tough, where are the figures for the toughness scale? Load Range is antiquated in my mind.
Much easier to understand and get behind Load Index Rating specs which provide actual data/numbers for X lbs of load per tire at X psi.
"higher ply rating tires *need* to run high pressure with a load because too much flexing will make them overheat."
Agreed that running any tire lower on pressure, especially under heavier loads, and at higher speeds = more friction = more overheating = more damage to tire. A helpful example is continuing to drive at 55mph on a flat tire. That tire is going to start coming apart and should not be re-used even after repairing the initial puncture.
Contradiction; you cleared it up here with this; "The tougher tire will tend to generate more heat, all else being equal."(pressure, load)
"But their[tougher tire, ie E vs D] ability to handle higher pressure allows them to carry a higher load."
Potentially true for some tires(see below at 37x13.5R18), but not true for many others(see below at 33x12.5R20) including the 35x12.5R17/E vs 37x12.5R17/D discussed here. For all of these 35"/E and 37"/D I've researched, these 37"/D-load tires will ALWAYS carry more load (per tire) than the 35"/E-load tire, across ALL possible pressures! This data of the 37x12.5R17LT vs 35x12.5R17LT can be seen here on the bottom of page31; https://www.toyotires.com/media/3729/application_of_load_inflation_tables_20200723.pdf
Also, seen here in regards to Peter's tire; https://www.tirerack.com/tires/Spec...5QR7GXAT&vehicleSearch=false&fromCompare1=yes
35X12.5R17LT
121 load index(3267lbs/tire), E load range(3195lbs MaxLoad, 65psi Max Inflation Pressure)
37X12.5R17LT
124 load index(3580lbs/tire), D load range(3525lbs MaxLoad, 50psi Max Inflation Pressure)
Now, here's an example of an E load range which has a higher max load than the D above;
37X13.5R18LT
128 load index(3970lbs/tire), E load range(3970lbs MaxLoad, 65psi Max Inflation Pressure)
(There are also some other Geo X-AT E's at 4080lbs at 80psi)
But here's an example of an E load range which has a higher max pressure than the D above, but has a much lighter load index;
33X12.5R20LT
114 load index(2640lbs/tire), E load range(2600lbs MaxLoad, 65psi Max Inflation Pressure)
Sadly, lots of misinformation out there; "....bigger tires with a higher ply rating can hold more air and, thus, can carry more substantial loads." (https://www.tireamerica.com/resource/guide-to-tire-load-range)
While the E vs D can hold more air, it's not always true that the E can carry more substantial loads than the D, as we see in data above of Yoko Geolandar AT-X in 35/E vs 37/D.
All this tire tech talk is hurting my head. How about another video Peter?
rruff
Explorer
The examples you are giving just show how important tire *size* is for load capacity. A big tire doesn't need heavy construction or high psi to carry a heavy load. Small ones do.
montypower
Adventure Time!
Truck campers are great for fun and work! Nearly 2,900lbs of trash hauled out... Really enjoy this truck!
6.2L has been performing excellent.
DickM
just a member
Thanks for all the time and effort you two have put into documenting this build. It has been informative and entertaining.
I too have spent a bunch of time researching additional fuel options for my 2016 Supercab with an Outfitter 6.5 slide in pop up camper, and, like you, have not liked any of the options I have found.
So, I would appreciate a quick, real world update on your satisfaction with your custom tank solution...... changes, if any, you would make in mounting, transfer method, capacity, etc. It is very appealing to me vs. a 30 gal tank hanging under the truck with the spare moved to a swing out bumper, or 4 fuel cans hanging on the camper itself.
montypower
Adventure Time!
Tank update:
1. Shaker Siphon method - takes about 10-12 minutes to transfer fuel to main tank. Time hasn't bothered me. I have thought about welding a hose fitting to the bottom of the tank with a ball valve to gravity feed into the main tank. Just not sure it's worth doing. Possible leak issues and cutting into factory fuel system. You could also install a transfer pump (however not interested in complexity and possible issues).
2. Useable fuel. Realistically, you can't completely fill the tank. Even though it is a 21 gallon tank. Figure 20 gallons of useable.
3. Siphon won't get everything out of the tank unless parked at slight angle. Sometimes I'll drain the tank down 4-5" (from the top) and parked at an angle to get nearly every drop from the tank (right about 20 gallons).
4. Vent issues. I extended the tank vent ~ 18". However, if parked at an angle (full tank) and fuel contacts the vent in direct sun (gas expansion) we've had fuel pressurize out of the vent. Solution. Is to drain tank down 3-4" from the top where there is more air space and so parking at angles doesn't cause issues. Really only an issue when parked with passenger side low in direct sun with a full tank. Hasn't been an issue with the camper (as it shades the tank).
How often do we use it?
Every fill up!! Even when staying local. It allows us to fill at Costco and save some money. We will often fill 50 gallons between the 2 tanks with range to spare. So 500 miles on average between fills. Our max range is 550miles if every drop was used. Once again, not practical. You shouldn't drain your main tank completely. So realistically, we have 32 gallons (main tank) and 20 gallons (aux tank).
I don't mind the siphon transfer process. Simple and reliable. You do need to hold the siphon to get all the fuel. And if you lose the siphon with less than half tank it would be very difficult to "restart" the siphon. So holding and watching is somewhat required if concerned about draining everything. I've let it self-siphon and probably left 3-4 gallons in the auxiliary tank when it's not important to transfer everything.
Massive game changer! Love the tank being fixed. Similar capacity to 4 fuel cans (terrible hassle). Fill is on the same side as the factory fill (easy to fill @ gas station). Love the spare remaining in the stock location (swing outs suck - why are they popular?). Best value option for simplicity, size and functionality. And easy to relocate to another truck or sell.
I used 4 rivet nuts to hold the tank to the bed. Easy to remove! Doesn't mess up the factory bed for resale.
1. Shaker Siphon method - takes about 10-12 minutes to transfer fuel to main tank. Time hasn't bothered me. I have thought about welding a hose fitting to the bottom of the tank with a ball valve to gravity feed into the main tank. Just not sure it's worth doing. Possible leak issues and cutting into factory fuel system. You could also install a transfer pump (however not interested in complexity and possible issues).
2. Useable fuel. Realistically, you can't completely fill the tank. Even though it is a 21 gallon tank. Figure 20 gallons of useable.
3. Siphon won't get everything out of the tank unless parked at slight angle. Sometimes I'll drain the tank down 4-5" (from the top) and parked at an angle to get nearly every drop from the tank (right about 20 gallons).
4. Vent issues. I extended the tank vent ~ 18". However, if parked at an angle (full tank) and fuel contacts the vent in direct sun (gas expansion) we've had fuel pressurize out of the vent. Solution. Is to drain tank down 3-4" from the top where there is more air space and so parking at angles doesn't cause issues. Really only an issue when parked with passenger side low in direct sun with a full tank. Hasn't been an issue with the camper (as it shades the tank).
How often do we use it?
Every fill up!! Even when staying local. It allows us to fill at Costco and save some money. We will often fill 50 gallons between the 2 tanks with range to spare. So 500 miles on average between fills. Our max range is 550miles if every drop was used. Once again, not practical. You shouldn't drain your main tank completely. So realistically, we have 32 gallons (main tank) and 20 gallons (aux tank).
I don't mind the siphon transfer process. Simple and reliable. You do need to hold the siphon to get all the fuel. And if you lose the siphon with less than half tank it would be very difficult to "restart" the siphon. So holding and watching is somewhat required if concerned about draining everything. I've let it self-siphon and probably left 3-4 gallons in the auxiliary tank when it's not important to transfer everything.
Massive game changer! Love the tank being fixed. Similar capacity to 4 fuel cans (terrible hassle). Fill is on the same side as the factory fill (easy to fill @ gas station). Love the spare remaining in the stock location (swing outs suck - why are they popular?). Best value option for simplicity, size and functionality. And easy to relocate to another truck or sell.
I used 4 rivet nuts to hold the tank to the bed. Easy to remove! Doesn't mess up the factory bed for resale.
mk216v
Der Chef der Fahrzeuge
I'm working on a 60gal tank solution for 6.2L. Hope to have some success by later this year, if not sooner.
Glad to hear you're still loving your 6.2L Peter. I'm loving mine!
DickM
just a member
Unfortunately, Ford, in it's infinite wisdom, only found room for a 26 gallon tank for the SuperCab diesel, so fuel is a real issue with a camper offroad.