F-150 20” wheels

[rmnpcolorado]

When I look at Ford’s towing guide for the 2018 F-150 SuperCrew 145” wheelbase 4WD with the 3.5L eco boost twin turbo and 3.55 gear ratio, there are three options:
GCWR of 16,100# = 10,700
GCWR of 16,700# = 11,000 (Limited package only& max tow package)
GCWR of 18,100# = 12,700 (requires 20” wheels & max tow package)

A) is the GCWR figure available somewhere that I am not finding or is it a calculation that I need to do?
B) is it really just by jumping to the 20” wheels adds a hypothetical 2,000# in tow capability? There has to be more to it than that. If not, how is that possible?

No, I’m not anywhere close to that. 10,700# would handle our trailer just fine. But to me, additional cushion is always better.

[BenK]

IMHO....the Age old adage: :a chain is only as strong as it’s weakest link’...meaning that in this case it seems the tires were the lowest rated link...

[Grit_dog]

Idk man. Seen plenty of HDPP F150s and srw 1 tons with 18s. But whatever you say...
Ever think that they offer 20s now on HDPPs or max tow or whatever because they’re popular?
Just remember, sex sells and dubs are sexier than 18s!
FWIW, you could over tire a half ton truck to tire capacities that would never be exceeded save for the stupidest human trucks out there. In anything from 16-20”.
Over n out.

[StirCrazy]

Grit dog wrote:

StirCrazy wrote:

Grit dog wrote:
These last 2 posts are false, OP.
It’s not the tires and wheels increasing the capacity unless Ford “chose” to add higher rated tires to the 20s.
Actually in general if the tire OD is the same (unless the 20s are notably taller), the greater the rim diameter, the lesser the sidewall height and the lower the load rating.
And besides people are confusing gvwr, aka payload, with tow rating that is increasing the gcvwr considerably without a large or any payload increase.
My “guess” is the 2klb tow increase is from lower gearing and may have mis-read or it misprinted.

I think you need to learn what you talk about. in 2014 nd several other years the increased gvw package in my canse 11500 was only available with the 20" wheels and that was the only thing different from the 11000 gvw package. yes they are bigger 34.6" and rated higher, both rim and tire.

Steve

A. We’re talking about F150s here so what you’re saying about your super duty doesn’t apply.
B. You can get the same load rating in an 18” tire of the same diameter, so again, 18or20 is of no real relevance to payload, apples to apples. Same with rims. Neither Ford nor the other mfgs have made a special high load rim. If they have, I’m all ears. Show me. I’d like that with my overloaded srw truck. But I don’t believe they exist in the OEs.
17” yes because noone makes heavy duty 17” tires anymore.

One of us needs to learn.........

Not it! Lol

laugh all you want but think about it. all it is showing is the fact that ford will give an increased payload to there truck rating with a biggere tire. yes I stated this in my F350 but the original poster was told this applies to the truck he is looking at. it is just coralation that indead ford does do this. and the 20 inch tires you get factory do have a greater weight raiting than the 18's. Can you get 18's that are just as high? yup but not from a factory offering and if you dont get the factory option you dont get the increased weight raiting on the sticker. which may not be a big deal for people in the US who can just pay a little more and carry all you want, but in canada we cannot alter the weight rating of the vehicle and are stuck with that as a max as a non comercial vehicle. I wish I could just go into the vehicle registry and add an extra 3000lbs to my capacity for 100 bucks like some people can.

Steve

[Grit_dog]

Groover, you missed the part of my quote that said “same OD”.
Seems a bunch of confused folks trying to prove me wrong. Rather than conjecture, compare the same DIAMETER and load range (E or XL or whatever) in different rim sizes. Yes to get the same diameter the tires will have a different aspect ratio.
And the larger rim with lower aspect ratio and same diameter will lose to the smaller rim and taller aspect ratio. Same width.
That said, with today’s truck tires in the 32-35” diameter range, there are plenty of high load rating options in 20” rims and moderate widths.

Extremely wide tires don’t necessarily have the same ratings. Like wider than 12”, in general.

[Grit_dog]

StirCrazy wrote:

Grit dog wrote:
These last 2 posts are false, OP.
It’s not the tires and wheels increasing the capacity unless Ford “chose” to add higher rated tires to the 20s.
Actually in general if the tire OD is the same (unless the 20s are notably taller), the greater the rim diameter, the lesser the sidewall height and the lower the load rating.
And besides people are confusing gvwr, aka payload, with tow rating that is increasing the gcvwr considerably without a large or any payload increase.
My “guess” is the 2klb tow increase is from lower gearing and may have mis-read or it misprinted.

I think you need to learn what you talk about. in 2014 nd several other years the increased gvw package in my canse 11500 was only available with the 20" wheels and that was the only thing different from the 11000 gvw package. yes they are bigger 34.6" and rated higher, both rim and tire.

Steve

A. We’re talking about F150s here so what you’re saying about your super duty doesn’t apply.
B. You can get the same load rating in an 18” tire of the same diameter, so again, 18or20 is of no real relevance to payload, apples to apples. Same with rims. Neither Ford nor the other mfgs have made a special high load rim. If they have, I’m all ears. Show me. I’d like that with my overloaded srw truck. But I don’t believe they exist in the OEs.
17” yes because noone makes heavy duty 17” tires anymore.

One of us needs to learn.........

Not it! Lol

[Groover]

StirCrazy wrote:

Grit dog wrote:
These last 2 posts are false, OP.
It’s not the tires and wheels increasing the capacity unless Ford “chose” to add higher rated tires to the 20s.
Actually in general if the tire OD is the same (unless the 20s are notably taller), the greater the rim diameter, the lesser the sidewall height and the lower the load rating.
And besides people are confusing gvwr, aka payload, with tow rating that is increasing the gcvwr considerably without a large or any payload increase.
My “guess” is the 2klb tow increase is from lower gearing and may have mis-read or it misprinted.

I think you need to learn what you talk about. in 2014 nd several other years the increased gvw package in my canse 11500 was only available with the 20" wheels and that was the only thing different from the 11000 gvw package. yes they are bigger 34.6" and rated higher, both rim and tire.

Steve

"people are confusing gvwr, aka payload, with tow rating"
That is both true and, arguably, false. Ford is increasing the tow rating without increasing the payload rating so the statement gets a true rating. However, the fact that 10 to 15% of the gross trailer weight should be put onto the truck means that in real life it is questionable. With the highest tow rating of 14,000lbs for the 2021 model that means that you should have 1,400 to 2,100lbs on the truck. That wipes out the payload rating even with nothing else in the cab or the bed of the truck. So there is a very valid argument that when you are using your crew cab pickup to haul the family and tow a camper on vacation you will exceed the gvwr before exceeding the Ford tow rating for the vehicle.

"My “guess” is the 2klb tow increase is from lower gearing"
This appears to be false. I can't find any new lower gear ratios in the 2021 build site. And even for previous years a higher tow rating could be achieved with 3.55 gears than the 3.73 gearset.

"the greater the rim diameter, the lesser the sidewall height and the lower the load rating"
This seems to apply more to the really low aspect ratio tires, lets say 40 and below. The factory tires for the 20" rims have a 60 aspect ratio and doing a little bit of research showed that the available tires for 20" rims and a 60 aspect ratio actually showed higher weight ratings than than the 18" tires for the same truck.

[StirCrazy]

Grit dog wrote:
These last 2 posts are false, OP.
It’s not the tires and wheels increasing the capacity unless Ford “chose” to add higher rated tires to the 20s.
Actually in general if the tire OD is the same (unless the 20s are notably taller), the greater the rim diameter, the lesser the sidewall height and the lower the load rating.
And besides people are confusing gvwr, aka payload, with tow rating that is increasing the gcvwr considerably without a large or any payload increase.
My “guess” is the 2klb tow increase is from lower gearing and may have mis-read or it misprinted.

I think you need to learn what you talk about. in 2014 nd several other years the increased gvw package in my canse 11500 was only available with the 20" wheels and that was the only thing different from the 11000 gvw package. yes they are bigger 34.6" and rated higher, both rim and tire.

Steve

[riven1950]

Our 2018 ECO CC XLT max tow was totaled is Sept during a hurricane. I had LT Michelens on it . Tires were 18 inch.

We replaced the truck with exactly same truck, 2020. The 2020 has 20 inch tires, which I was not really excited about at first. The tires are stock OE ford tires. I really have changed my mind and love the look and ride of the 20 inch tires. Have not been able to tow with it yet due to illness, but i'm betting the 20's will tow better.

[Groover]

JIMNLIN wrote:
Looking at 2020 fleet ford specs show the 18" X 7.5" wheels are OEM on the F150HDPP. The specs also shows the 20"X 8" wheels have less capacity than the 18". These are all 6 lug wheels.
Can the F150HDPP with its 4800 rawr be had with 20" wheels (2026 lb rating per Ford specs). Granted the tires may have enough capacity but the wheel requires at least a 2400 lb rating to be used with the HDPPs 4800 RAWR.

HDPP can only be had with 18" wheels through the 2020 model but changes for the 2021 model. Some combinations seem to be available with the 20" wheels. I just built a Lariat hybrid and it shows the 3.73 axle which goes with Max Payload and 20" wheels. No LT tires though. So if you are considering 2021 model things are changing.

Lariat, SuperCrew®, 6-1/2' Box, 3.5L Power boost™ Full Hybrid V6 Engine, HEV Electronic Ten-Speed Automatic Transmission with Selectable Drive Modes, 4x4, 3.73 Electronic Locking Axle Ratio $51,945
Edit
PaintS4
Antimatter Blue$0
No Secondary Color$0
Edit
PackagesS4
502A High$6,920
Max Trailer Tow Package$1,350
275/60 R20 OWL All-Terrain Tires (A/T) (4x4)$0
Exterior S4
20" Chrome-Like PVD Wheels $1,395

[Grit_dog]

BB_TX wrote:

Grit dog wrote:
These last 2 posts are false, OP.
It’s not the tires and wheels increasing the capacity unless Ford “chose” to add higher rated tires to the 20s.
Actually in general if the tire OD is the same (unless the 20s are notably taller), the greater the rim diameter, the lesser the sidewall height and the lower the load rating.
....

Sorry, not true for all tires. Look at the specs for the Michelin LTX A/T2 tires in LT275/65R18 and LT275/65R20. The 18" tire has a max load rating of 3,415 lbs at 80 psi. The 20' tire has a max load rating of 3,750 lbs at 80 psi. That is 335 lbs more per tire than the 18".

Similarly, the LT245/75R16 tire has a lower rating than the LT245/75R17.

Similar Continental tires have the same load ratings as above for the same sizes.

Don't know about other brands or styles.

Michelin

That’s because they’re not the same height tires. The 20s are 2” taller than the 18s. They have the same sidewall height and greater OD thus more capacity.
I said same diameter tires. Same for the 16 vs 17 example.

Facts. And it’s more about physics than tire construction or brand. Same tire construction, greater width, sidewall, OD generally have greater capacity.

[BB_TX]

Grit dog wrote:
These last 2 posts are false, OP.
It’s not the tires and wheels increasing the capacity unless Ford “chose” to add higher rated tires to the 20s.
Actually in general if the tire OD is the same (unless the 20s are notably taller), the greater the rim diameter, the lesser the sidewall height and the lower the load rating.
....

Sorry, not true for all tires. Look at the specs for the Michelin LTX A/T2 tires in LT275/65R18 and LT275/65R20. The 18" tire has a max load rating of 3,415 lbs at 80 psi. The 20' tire has a max load rating of 3,750 lbs at 80 psi. That is 335 lbs more per tire than the 18".

Similarly, the LT245/75R16 tire has a lower rating than the LT245/75R17.

Similar Continental tires have the same load ratings as above for the same sizes.

Don't know about other brands or styles.

Michelin

[mooky_stinks]

The hdpp only comes with 18" wheels which makes this even more confusing.

[JIMNLIN]

Looking at 2020 fleet ford specs show the 18" X 7.5" wheels are OEM on the F150HDPP. The specs also shows the 20"X 8" wheels have less capacity than the 18". These are all 6 lug wheels.
Can the F150HDPP with its 4800 rawr be had with 20" wheels (2026 lb rating per Ford specs). Granted the tires may have enough capacity but the wheel requires at least a 2400 lb rating to be used with the HDPPs 4800 RAWR.

[rmnpcolorado]

mkirsch wrote:
It would be easy to determine by going to a lot and looking, that the load rating of the 20" tires is higher than that of the 16"/17"/18" options.

One would think that, but there’s a dealer I peruse that posts a picture of the labels and it’s not the case. There doesn’t seem to be much of a rhyme or reason as I tend to peruse the same type of trucks, all similarly equipped, all with the 7000#payload package as the window stickers say and they’re all different. 18s or 20s, who knows.

I was talking to a dealer and had him snap a picture of the label. It came back as 1,651lbs with the 18s. It seems like 1,800 is common, but so is anything below.