The North America owner's manual is defining specifications for a concept I have not before seen -- a "light load" (5 seat version - up to 3 occupants; 6 seat -- up to 4 occupants; 7 seat -- up to 4 occupants). The specified pressures are the same, regardless of the number of seats. For a light load, the tire pressures are: FRONT - 34 psi (2.3 bar, 230 kPa), REAR - 37 psi (2,5 bar, 250 kPa). These values are NOT documented on the driver's side sticker.

The door jam sticker ONLY includes "Normal" load pressures: FRONT - 47 PSI (3.2 bar, 320 kPa) and REAR - 50 psi (3.4 bar, 340 kPa). "Normal" is defined in the manual as having one more occupant than the light load definitions. Again all pressures are the same, regardless of the number of seats. The maximum allowed tire pressure on the sidewall is 50 psi.

Thus, it appears an additional 200 lbs. load requires an extra 13 PSI in both front and rear? Ummph.... Really? While I am sure this gives better gas mileage, maybe it contributed to the harsh ride quality I felt on day 1?

So, on my coming four hundred mile "lightly loaded" trip, I will set the pressures to "light" and see how it affects the ride. The TPMS system is configurable by the driver to choose either light or normal -- so low pressure warnings are avoided. So, I will set it to "light".

Coming out of the shop, you may want to specify to the mechanic whether you desire what is on the door jam -- "Normal" --- or what is suitable for a "light load". Enjoy!

 

It’s easy to change in the menu but only lets you chose from “normal” or “light” and gives no explanation or definition in the menu. But if you go into the tpms readings screen you can see that the pressure specified in parenthesis as nominal has changed. On street tires i keep our disco just above 41 all the way around (i think)and set at normal and the warning stays off but i will still het an early warning if it’s going low. I set it to “light” when i put the offroad tire set on so I can run much lower psi.

 

All four tires were overinflated when I took delivery of the Defender and checked pressure the following morning in my garage - 52 psi (cold) all around. Definitely check - they may be keeping them overinflated in their lot for a reason (to avoid flatspotting), but if they forget to adjust before delivery the ride does get harsher - not to mention handling and tire wear may also be affected.

 

4500 miles on mine, and with the tires I've swapped (Toyo AT3s) I'm finding 43 front / 47 rear is the sweet spot for highway driving. I know a lot of engineers spent a lot of time on the vehicle, but I think the stock recommendation on the door panel is a touch too high on the PSIs as to the OPs point the ride was pretty harsh at times.

 

I do suspect the pillar sticker determines the pressure at which miles per gallon is formally claimed and this is defined in some regulation as needing to be the "normal" state --- maybe this, and the California MPG regulations, are the trigger for what is typed on the sticker? For it makes no sense otherwise, I think.

Thanks all for sharing your decisions on good pressures to maintain. I have lowered mine and will be taking to the interstate and in town driving and hope the ride is better.

More sharing after the testing !

 

i think you are spot on for the pressure ratings being for mpg over comfort. No way to confirm this formally that I have found. I feel like watching tire wear of center treads vs outside treads used to help you find nominal pressure. But tires have improved so much that it takes a while to learn from wear patterns now lol.

 

I just finished a couple hundred miles of freeway driving with the Good year Wrangler AT Adventures set at 43 psi rear and 40 front (7 PSI under the "Normal" in the manual) and it made a HUGE difference in ride quality -- much better.

Thanks all for the advice and info.

 

I always put 36 PSI on all 4s unless I'm towing or fully packed with stuff that I inflate the rear tires 40 PSI.

 

I’m also a little confused about this:
The “tyre information” displays the load settings as “light” and “normal”...however, The manual/i-guide lists these setting as “light” and “heavy”


I’m guessing this is just an oversight with the terminology and that “heavy” and “normal” are referring to the same.

 

I’ve used light and “normal” with the Adventures, and I prefer the tighter handling of the higher setting. I’m used to tight handling European sedans anyway, so the ride is fine. Light doesn’t corner as well. Also, remember that if you’re towing or carrying a lot of stuff, should probably be on the higher pressure.