Tire Pressure Help - Mickey Thompson 285/70/17s

Gents, just got some new shoes today. Wondering what the correct on-road tire pressure for Mickey Thompson 285 70 R17s C load is?

Grateful for you.

 

35PSI

 

Which tire did you buy? I didn't know mickeys made 285s in c load?

 

285/70R-17 MICKEY THOMPSON BAJA BOSS A/T SL - So SL Load which I thought was C load.

 

Thanks Loco!!

 

You can get them in the 285 standard load. Only 4lbs difference between 265/70/17’s.

 

Load C is a Light Truck tire rating, which generally need to be run at slightly higher pressures than standard load tires. I’m guessing, yours should be run closer to factory tire pressures.

 

from the manual:
Check that the number given by dividing the maximum load by 1.10 of
the replacement tire is greater than 1/2 of the Gross Axle Weight Ratings
(GAWR) of either the front axle or the rear axle, whichever is greater.
For the GAWR, see the CertificationLabel. For the maximum load of the
tire, see the load limit at maximum coldtire inflation pressure

correct pressure can be found in LT tires pressure table, I used Toyo tire table, but I guess it's the same for other LT tires:

Tire Load Limits (lbs.) at Various Inflation Pressures (PSI) - LT285/70R17

35 40 45 50 PSI
2105 2315 2510 2755 Lbs


So 35 psi should be enough, but I wouldn't go much lower for long highway driving since all tables never shows anything under 35psi for LT tires. Probably load capability drop is not linear and LT tires load is different from P-metric tires. When I had stock side LT C load tires I ran them on 36-38 psi, but it was for stock size and stock size has 1925 lbs on 35 psi my SR5 needed minimum 1719.5 lbs per tire.

 

35 it is! Appreciate y’all!

 

Wait, I thought it was established they were SL loads, not an LT285 C load?

I have rugged trek SL load 285/70s and the online tire pressure calculator said to run them at 26 PSI.

They were filled to 38 when mounted but didn't touch the road about 1" from each edge, and also rode like rocks. I dropped to 28-30 and they ride much better and now wear all the way across. SL is basically the same as P load (stock) so the larger footprint requires less PSI for the same weight

Or am I just driving around now on flabby tires? 28-32 looks and feels right

 

LT tires generally need more pressure

 

Mine seem to be not touching about the same 1 inch from the sides. They’re at 35 right now. Here’s the Mickey Thompson link.
247502 is the model number. it says 44psi but at 35 it’s not touching on the edges. So I’m confused a bit.


https://www.mickeythompsontires.com/light-truck-tires/baja-boss-a-t

 

That chart is telling you what the maximum load is at maximum inflation of 44 psi. Maximum inflation is not the recommended inflation for your vehicle at standard load. That will be closer to your factory door sticker and possibly lower as mentioned earlier due to your tire size being wider than OEM which will distribute the same load across a larger surface area.

 

Add some pictures....I want to see them. This is the next set I am thinking in getting.

35psi is what I think most people run these things at. I have to be honest, I can't ever get straight all of this C, ST, LT, loads, rating,...blah..blah. So much lingo and terminology that I wonder if it is tactics to keeps us all confused.....because if you look at the ownership of these tire companies...they are owned by just a few of them with a bunch of rebranding names thereafter. Anyway, congrats on the set. Hope you tell us how they feel.

 

Thank you. That is helpful. I’ll upload some pics tomorrow

 

Amen!

 

Just switched from 285/70/17 KO2’s C-Rated to Mickey Thompson Baja Boss AT’s LT-Rated.

Liked these tires so much I put them on both our 4Runners.

Anyway, started at 42psi, dropped to 40psi, to 38psi and now settled on 35psi for both rigs.

Needed to get to 35psi for a comfortable ride.

 

Tried this and it came up with 26PSI
If anyone wants to help double check my work that would be amazing. Just want to do what’s right for these.

 

@raimieb excellent tire choice my friend!
I opted for big daddy LT load E this time. 285/70
Tires say 80psi max haha
My Baja ATZ's were replaced by MT with the Baja Boss
I run 38psi now, I was at 36
Door says 32psi for passenger 265's, so irrelevant

 

I re read this about ten times. Now I see what you’re saying. Mine came up with 26PSI also on the calculator.

thanks DJ! Actually, seeing your posts pushed me to get it done!! So funny you wrote because I thought of your rig today when getting them put on. Appreciate you. Yeah, I’ll try and fiddle with the psi in the morning as well as mudflap delete to avoid the rub. Then report back. Appreciate you brother!

 

38 if you go by the calculator on tiresize.com. I have Toyos in the same size and load range, and tend to run them at 35.

Most folks will run lower pressure than what's recommended.

 

I agree with James, and the calculator thing. But if you go by the calculator, you would need to weigh the front and rear loaded and empty. Then also that needs to be adjusted for mods. Bumpers, winches, slider’s, and stuff. Then i have still noticed that my tires are not running full tread on the road, so to keep with the i adjust the air accordingly, chalk test, dirt test or whatever, i want all the tread front and back on the pavement. Hey, I’m old, change is hard for me. Oh shit, i almost forgot to add, i do not sell tires for a living, and i like when mine are wearing even.

 

I know I'm always pushing the calculator, but I ran lower pressure in my KO2's, and it seemed to work out fine.

I definitely agree that it makes more sense to go by the actual running weight of your vehicle than by GVWR.

 

I need help with my KO2 Load E 285/75/R17s. Guys, help!

 

Off topic, but how do you like these tires so far?

I'm thinking of getting these in this size and SL for mine too. Personally I would start with 35 PSI.

 

Just on today. Need to adjust and retry. Going with chalk method today to test and will report back. I have them on my Toyota Sienna and they’re beasts, which I like.

 

Been running mine at 35psi with no issues.

 

You have these on a Sienna?? Badass! I need to see pics of that!

 

Been running my 265/70/17’s at 35 and ride nice and no road noise. Also great in the snow which I tested in about 5 inches a few weeks ago. I was planning at first not to go to 285’s but knowing they are only 4lbs difference I may switch them out down the road.

 

Same 285 size? If so you getting full contact on all edges?