Newb - tyre pressures, two door stickers with differing pressure recommendations? (1 Viewer)

[bart0]

Hello. First time larger-than-hatchback owner of a '96 GXL and confused about tyre pressure recs on inside door jam panel. There are two stickers with differing pressure recommendations. Is this normal, is one for 'roads' and another for off-road?

To complicate things the previous owner used the car only for highway towing, and it has almost new Yokohama Geolandar H/T "Highway" tyres on it on aftermarket rims at 17" (OEM =16"). According to tiresize.com/pressure-calculator the OEM size 275/7016R and the new wheel/tyre size 275/65/17R says they are basically the same (a few % difference). Does this seem correct?

Can anyone please shed some light on:
1. The two stickers and what I should be setting my pressures at for general road driving?
2. When towing 2.5 tonne horse float should I be upping the rear tyre pressures a bit?
3. Does the similar pressures for OEM vs current wheel/tyre size seem right?

Thanks!

 

[sbman]

Different types and sizes of tires will have different recommendation, the tires are considered part of the suspension of the vehicle and each tire type and size will have different recommended pressure for the same vehicle application..

The first sticker has tire size format that I don't know of, it's not ISO Metric, P Metric, not LT-Metric or Flotation, but it is specifying the pressures for that particular size tire, whatever it is.

The second sticker is for an ISO Metric size, 275/70R16. An ISO metric tire at 220 kPa (31 psi) and a load index of 114 has a load capacity of 909 kgs (2006 lbs).

You can convert from one tire size recommended pressure to another, but you have to know the specific size that is on the vehicle to do so and then look at an inflation table to do the conversion from a known tire (such as the ISO Metric the second sticker has) to the new tire size.

 

[greentruck]

Tire pressure is very much dependent on which load range the Yokohamas are. Most tires in these size range are either Load Range C or E. For BFG, there's a list of all the tire sizes in say BFG KM3:
Shop Mud Terrain T/A KM3 Tires | BFGoodrich Tires - https://www.bfgoodrichtires.com/auto/tires/mud-terrain-t-a-km3
Look under the menu heading Available Sizes and you'll see they are all either C or E. C range tires tend to have significantly lower pressure maximums (65 lbs) than E rated tires (80 lbs). Then you can adjust your actual pressure to reflect how much of the actual carrying capacity you are placing on the tires. In my case, I ran Load Range E KM3 at about 45 lbs (on a max of 80 lb available) on the highway.

 

[Rusty Marlin]

The first sticker is for narrow little pizza shaped tyers. I've never seen that tyers size either.
if you have diffent size tyres than the stock sticker you can do a chalk test to make sure the inflation pressure is right.

How To Find The Right Tire Pressure For Your 4x4 Using Chalk - The Dirt by 4WP

Improve Fuel Economy, Tire Life, Traction And Vehicle Ride With Proper Tire Pressure

www.4wheelparts.com

 

[80t0ylc]

The most conclusive difference between the 2 stickers that I saw was the recommended rim size. On the 1st sticker, it doesn't say "recommended", it just says "rim size", which is 16 X 5.5. The 2nd sticker calls out 16 X 8 JJ which at least here in the States, is typical of stock for the 80 series. But have to agree with OP, kinda weird. Why 2 stickers?

 

[80t0ylc]

To answer my own question, I guess 2 stickers gives the owner a choice of tire sizes they can run. The narrower 5.5 width (pizza cutters as @Rusty Marlin says) would be for better for fuel mileage. Best to run tires that are suited for your rim width for tire performance and longevity. Most tire stores can supply specs for what tires you can safely run for a particular rim width and also inflation recommendations, although the chalk test is a reliable method.

 

[Rusty Marlin]

top sticker is for bias ply tyers.

 

[chap79]

“The 7.50-16 tire size is a designation for agricultural and commercial tires, plus a few specialty industrial tires.”

 

[bart0]

Thanks for the info everyone! I'll set it up according the the Toyota recs, converted to my new tyre size ~32psi. Will also do the chalk test which I didn't know about once the car is up and running post-roadworthy certificate. Appreciate the help!