RESOLVED: Wheel and Tire Pre-Purchase Technical Questions

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Solace in Solitude

Solace in Solitude

10 Year
Joined
Feb 4, 2014
Threads
125
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7,185
Location
Las Vegas
I am preparing to order new wheels and tires and have a few FJ40 specific questions that I could really use some insight on...

My '78 FJ40 has front disc brakes ...
  • I was planning to upgrade to 16" wheels, but am really having trouble finding 16" with < 4.0" backspacing... I don't want to run spacers if I don't have to... the wheels I'm considering are steel 15x7" 6x5.50" lugs 4.25" centerbore 3.75 backspace ... am I missing anything important?
  • I was also thinking about buying load range E tires (KM2 or KO2... probably KM2), but unless I upgrade to 16" wheels, I can only find load range C KO2s and KM2s in 15"... But, in rethinking this, I think, "load range C will actually flex better for 'airing down'" - am I right that load range C is fine for off-road? It's been fine with the MasterCraft Coursers that came on 44.
  • I'm planning to go with KM2s in 33x10.50R15... that will add about 1 1/8" in height... these should give me a cheap overdrive and maybe a little fuel economy improvement... I know I have sufficient clearance, with my air bags... are there any other issues I need to consider?
Thanks!!
 
Danny you covered it all. I agree with keeping the 15" wheels and just upgrade to 33" tires.
 
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If I'm not mistaking, the stock backspace is 3.5 inches. I've seen 1/4" wheel spacers for cheap. Some one with more smarts will surely chime in. I just want to see pics of 44 with new boots on.
 
skidplate said:
If I'm not mistaking, the stock backspace is 3.5 inches. I've seen 1/4" wheel spacers for cheap. Some one with more smarts will surely chime in. I just want to see pics of 44 with new boots on.
Click to expand...

Yeah... 3.50" backspace is oem... but, VERY hard to find... 3.75 should be fine... if I have to run a 1/4" spacer, I will... but nothing larger.

You'll definitely see pictures... but, it will be a while... gotta order the wheels.

Thanks!!
 
After a lot of research the option I settled on was new Toyota 16X6 steel wheels from the 70-Series Land Cruisers - very similar in appearance to the Toyota chrome spoke FJ6/FJ62 wheels. They're kind of pricey but they look great! I mounted BFG LT235/85R16/E All Terrain KO2s. 15" tires are harder and harder to come by these days, especially tall skinny tires.
 
Just make sure the rims you buy have a good finish on them.i bought five new stock rims . the paint on them looked kind of thin but decided to just go with it .it was a mistake after a year its obvious I should have had them powered coated.
 
4Cruisers said:
After a lot of research the option I settled on was new Toyota 16X6 steel wheels from the 70-Series Land Cruisers - very similar in appearance to the Toyota chrome spoke FJ6/FJ62 wheels. They're kind of pricey but they look great! I mounted BFG LT235/85R16/E All Terrain KO2s. 15" tires are harder and harder to come by these days, especially tall skinny tires.
Click to expand...

What's the backspacing on these wheels?

Thanks!!
 
CarDude said:
Just make sure the rims you buy have a good finish on them.i bought five new stock rims . the paint on them looked kind of thin but decided to just go with it .it was a mistake after a year its obvious I should have had them powered coated.
Click to expand...

They ones I'm considering are powder coated.

Thanks!!
 
Solace in Solitude said:
What's the backspacing on these wheels?

Thanks!!
Click to expand...

Toyota Part Number 42601-60262-03 grey 16x6JJ steel rims with 3.75" backspacing - from what I understand they're powder coated at the factory.

Wheel.webp
 
Danny,
4cruisers beat me to giving you the part number for those wheels-I was looking at my notepad of saved factory part numbers for the part number. I'm probably going to those in the future on one of my trucks. Look at the 255/85/16 tire size as well- think they are a little wider than the 235s about the same as 33/10/16s. JohhnyC runs them on splits on his ride might check his pics for a visual. They will be a little wider on the 70 series rims vs. the splits...
HTH,
Will
 
Danny,
There are load range C, D, and E rated tires made in 16 inch sizes... I have 265/75/16 C range Goodyear Wrangler Authority tires on my DD 1/2 ton suburban. They are only sold at Walmart however and are also made as a E range in the same size for a higher price. But they are a little loud on the highway- I can't hear the big block flowmaster over the tires...
HTH,
Will
 
CarDude said:
Just make sure the rims you buy have a good finish on them.i bought five new stock rims . the paint on them looked kind of thin but decided to just go with it .it was a mistake after a year its obvious I should have had them powered coated.
Click to expand...

That settles it - I'm painting my black stock rims! Um, or maybe powder coating. Hmm-m-m...
 
tlc762 said:
Danny,
There are load range C, D, and E rated tires made in 16 inch sizes... I have 265/75/16 C range Goodyear Wrangler Authority tires on my DD 1/2 ton suburban. They are only sold at Walmart however and are also made as a E range in the same size for a higher price. But they are a little loud on the highway- I can't hear the big block flowmaster over the tires...
HTH,
Will
Click to expand...


Thanks Will!!

I saw KM2s and KO2s in C, D and E, in 16"... but only C is available in 15"... but, I'm convinced I'm better off, off-road, with load range C. I air down and the Cs will flex more and not be as likely to break a bead... plus, I've had no trouble with the Cs that came on 44 when I bought her.

I really wanted to stay with 15" rims anyway...
 
I'm old school, I grew up with ply ratings. That being said, I looked up ply ratings and letter equivalency rates. Load ranges C, D, and E are equal to 6 ply, 8 ply, and 10 ply ratings. I have load E (10 ply) tires on my 3/4 ton pickup, which happen to be very stiff sidewalls. A couple years ago I loaded up concrete cores in my pickup. Driving home I could tell that the load was much heavier than I had estimated. I weighed several cores and came up with about 8K pounds I had in the pickup. The load E tires had shown some weight at 70 pounds of air, but not 8K pounds worth.

In the past I've primarily used 8 ply tires (load range D), which are also stiff, but not as stiff as E rated tires. I also use load C tires on my Astro vans. In my opinion what would work best for your needs would be load range D (6 ply) tires. The side wall has some flexibility to it, not so stiff that the lack of flexibility creates problems for you when going over rough terrain, but strong enough to hold up to rough terrain. Load range D and E are way too stiff for the weight of 44.

Don
 
handcannon said:
I'm old school, I grew up with ply ratings. That being said, I looked up ply ratings and letter equivalency rates. Load ranges C, D, and E are equal to 6 ply, 8 ply, and 10 ply ratings. I have load E (10 ply) tires on my 3/4 ton pickup, which happen to be very stiff sidewalls. A couple years ago I loaded up concrete cores in my pickup. Driving home I could tell that the load was much heavier than I had estimated. I weighed several cores and came up with about 8K pounds I had in the pickup. The load E tires had shown some weight at 70 pounds of air, but not 8K pounds worth.

In the past I've primarily used 8 ply tires (load range D), which are also stiff, but not as stiff as E rated tires. I also use load C tires on my Astro vans. In my opinion what would work best for your needs would be load range D (6 ply) tires. The side wall has some flexibility to it, not so stiff that the lack of flexibility creates problems for you when going over rough terrain, but strong enough to hold up to rough terrain. Load range D and E are way too stiff for the weight of 44.

Don
Click to expand...


Thanks for the validation, Don!! Albeit, with a typo ;) - you meant load range C (6 ply). I agree, I'd hate to air down and break a bead on tires with stiff sidewalls. I run 10-ply on both my Tundra and my travel trailer and am very happy with them. But, I don't drive them on the terrain that 44 sees.

Thanks!!
 
Solace in Solitude said:
  • I was also thinking about buying load range E tires (KM2 or KO2... probably KM2), but unless I upgrade to 16" wheels, I can only find load range C KO2s and KM2s in 15"... But, in rethinking this, I think, "load range C will actually flex better for 'airing down'" - am I right that load range C is fine for off-road?
Click to expand...

Yes, load-range C will air down and flex better for sure. I ran 34" E-range Toyo mud terrains on another truck heavier than a 40 (my FJC) and they lasted forever and never had a flat, but the sidewalls were way stiff and I would have to air them down to 8 or 9 PSI to get them to flex at all. They're made for much heavier trucks. For comparison, I've had 33x10.5x15 range C KM2's on my 40 for years, and they flex really well when aired down to 14-15 PSI.
 
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