Don’t air down Cooper tires!

ExplorerTom

Explorer
Awhile ago I emailed the “contact us” on the Cooper Tire website and asked the following

I have a 2000 Ford Expedition that weighs approximately 5000-5500 lbs (maybe more once loaded up). I use it for camping and offroading. I have a set of Cooper Discoverer ATP tires in 275/70/18 Load Range E. What pressure should I be running on the street? Also, it’s common to air down while offroad for better traction and ride comfort. Do you recommend this? And approximately what should I be airing down to for rocky terrain? Thank you Tom
This is the reply I got from the Consumer Relations Department:

Thank you for your email. Always follow the air pressure recommendation of the vehicle manufacturer as listed on the placard in the door of your vehicle. Proper air pressure is based on the weight of your vehicle and is determined by the vehicle manufacturer, not the brand or type of tire you have. Also, never exceed the max air pressure as listed on the sidewall of the tire. I have included a load and inflation chart for your tire size.

If you have questions regarding this or need more information please contact your vehicle manufacturer. There are several sites you can refer to as well regarding tire pressure safety.

www.ustires.org
www.nhtsa.gov
www.safercar.gov


Pamela
Consumer Relations
800-854-6288 M-F EST.
Not happy with that boilerplate reply, I replied with this:

Pamela,

Thank you for your response.

I was hoping to get my question in front of someone more technical than the consumer relations department. I understand that the placard on my vehicle was developed by the manufacturer for on road use. However, I use my vehicle in other conditions than smooth, paved roads. Running street pressures in rocky conditions is bad for traction and bad for the tire.

Can you pass this inquiry off to the engineering department?

Thank you
—Tom
Here’s her response to that:

Sorry Tom, but an engineer cannot answer your question. We do not recommend running pressures below the door placard recommendation.

Pamela
Consumer Relations
800-854-6288 M-F EST.
So, there you have it. According to Cooper: they do not recommend airing down tires below your door sticker.
 

Recommended books for Overlanding

Long Way Round: Chasing Shadows Across the World
by Ewan McGregor, Charley Boorman
From $14.59
Adventure Motorcycling Handbook: A Route & Planning Guide
by Chris Scott
From $10.09
Motorcycle Messengers: Tales from the Road by Writers who...
by Lois Pryce, Mark Richardson, Carla King, Sam Manic...
From $9.99

shade

Well-known member
of course, that's just their legal department deflecting liability.. what do you expect, tire companies deny warranty coverage for off road tires used off road.

This is why it was ford's fault explorers are known as exploders.. IIRC Goodyear got off pretty lightly other than the brand damage.
Firestone, and what a mess that was. At least it helped deliver the joy of TPMS to the masses.

OP, I doubt you'll get a different official answer from any tire manufacturer, even if airing down when driving offroad can actually protect a tyre. Cooper doesn't seem to have a problem with airing down here, but in legalese, they're just driving over a spike in controlled conditions.

 

ExplorerTom

Explorer
^I’ve seen that video. The YouTube account for it seems to indicate that it’s their Australian division that put out that video. Don’t know if it matters.
 

Peter_n_Margaret

Adventurer
Any tyre that can not be "aired down" is useless in any serious off tarmac use.
Simple response - don't buy Cooper tyres.
BTW, I use Michelin 305/70R19.5 XDE2 tyres on our off road vehicle. They publish full off road load/speed/pressure requirements for their tyres.
Cheers,
Peter
OKA196 motorhome
 

DaveInDenver

Expedition Leader
Last edited:

BritKLR

Kapitis Indagatoris
I'll raise you one tire company legaleze mess......BFG.

I have a 1995 Provan Tiger on a Chevy chassis. It had factory 15in wheels/tires. I lifted it and added 17 in OEM wheels and new BFG AT tires. A year later all the tire cracked on the shoulders at the tread. Going back and forth with the dealer and BFG and they finally replaced for $220. But they were very insistent and would not fully warranty the tires due to the larger tire /wheel combo was not designed for that year truck and therefore the tires did not perform as expected and therefore was operator error......BFG lesson? Do not put oversized tires on any vehicle that was not designed for them....wrap your off-roading head around that one....
 

ultraclyde

Observer
Meh. I've aired down Cooper AT3s with good results and will continue to do so. They're just covering their legal butts. I recently emailed them about street pressure on my new E rated AT3 XLTs and they responded with some similar boilerplate and links to the national tire association size/load charts. Which is fine, I can use those charts to calculate my preferred pressures - based on the factory tire size and door pressure, then adjusted for the load rating on the new tire size. How on earth would they even begin to make recommendations for aired down use off road given the myriad variations in load, surface, and equipment? Even if they told me a pressure, I doubt I'd trust it because they don't know the exact situation. Driving off road almost certainly means using products outside their design parameters and you either accept that (and the lack of warranty implied) or leave the vehicle stock, inflate the tires to door pressure, and stay on pavement.

I work in R&D for a company that sells retail consumer products. In today's litigious society we sure as heck aren't going to publicly tell you it's ok to use a product in any way other than what the legally-checked label advises. On some products that are Federally registered, it is actually a federal crime to use a product in a way that is not explicitly described on the label. Now, as the guy that makes the product, I know it's effective to use in a lot of other ways, but I'm not about to tell you to do it. We get frivolous lawsuits on a regular basis even when we take the legally conservative approach.
 

shade

Well-known member
Any tyre that can not be "aired down" is useless in any serious off tarmac use.
Simple response - don't buy Cooper tyres.
BTW, I use Michelin 305/70R19.5 XDE2 tyres on our off road vehicle. They publish full off road load/speed/pressure requirements for their tyres.
Cheers,
Peter
OKA196 motorhome
Interesting.

Do you have a link to that spec sheet?
 

Recommended books for Overlanding

We Will Be Free: Overlanding In Africa and Around South A...
by Mr Graeme Robert Bell
From $20
The Longest Line on the Map: The United States, the Pan-A...
by Eric Rutkow
From $13.39
Tortillas to Totems (Every day an Adventure Book 4)
by Sam Manicom
From $9.99
Road Fever (Vintage Departures)
by Tim Cahill
From $6.99
Motorcycle Messengers: Tales from the Road by Writers who...
by Lois Pryce, Mark Richardson, Carla King, Sam Manic...
From $9.99

shade

Well-known member
Perhaps the Truck Tire Databook is what you're after?

https://www.michelinb2b.com/wps/b2bcontent/PDF/Truck_Tire_Data_Book.pdf

It's a comprehensive source but the answer is something it seems you still have to figure out implicitly for an on-road (e.g. non-speed limited Y or L types) tire run below typical street pressures on unimproved surfaces.
Thanks. After a quick scan on my phone, I didn't see anything about pressures for offroad use, which seems to be what Peter was referring to earlier. Good information, though.

I was wondering what disclaimers and qualifiers were included, and if it was country specific. Putting the calculus on the end user is another way to distance a company from liability, too.
 
Last edited:

Buliwyf

Viking with a Hammer
Please quit being douchy to the support people. Not cool.

No tire company can officially say that a DOT tire can be safely air'd down then abused off road. There's liability involved. Pitbull and Maxxis might be able to get away with such, because those tires may not be intended for the street.

If you're airing down tires, you should have went to the Cooper Stt or St Maxx that are better meant for it with thicker sidewalls and rim protectors. I doubt you'll see much improvement airing down little Atp's.

This is why I have to bust my arse trying to get FORSCAN to link up to my computer and ECM to disable the useless obama light on the dash. Dumbest truck feature ever.
 
Top