Hi Fellow members. The tires on our SC are 245/35/19 in front and 275/30/19 in the rear. The brand are NEXEN Fera su1. The recommendation on the tag on the car door shows 230kpa which equates to 33psi. That reference is probably for the original run flats. After checking for the recommended tire pressure above, I should be running them on at least 40psi but not greater than 50psi. If any one has similar tire size what pressure are you running at?
Thanks.
Chris......From OZ.

 

I have 20 inch staggered I run 34 in front and 38 in rear

 

You can run 40-50 psi, but your ride comfort will be poor. I run 35 psi to get a good balance of performance and comfort.

 

Where did you find the tire pressures you post (between 40 and 50 PSI)?

Here's a site I've used in the past. Tire Pressure Calculator (tiresize.com)

 

Hi Lee, I checked on the computer for my particular tire size and brand as listed in my post above.
Chris.

 

What does the door sticker say and what are the tire specs it lists

 

Hi Lexo98, refer to my original post everything is listed there.
Regards.....Chris

 

Does it show the load index?

 

Hi, the load index that I have on the sticker is 230kpa or 33 psi for 245/40zr/18. Now that's for the original tires, assuming they were runflats. When I purchased our SC 6 years ago it came with low profile tires. The front 245/35zr/19 and the back ones 275/30zr/19. I was putting 33psi as per the sticker until I recently had a slow leak. When I got it fixed that's wen I was told that the tire pressure was too low being low profile and should be around the 40psi mark.
Chris.

 

In the US the load index is indicated by a number, usually near the speed rating (H, ,V, W, etc.) An example would be 95 H (where H is the speed rating). This means the tire can support a maximum of 1521 lbs.

A generally followed rule of thumb is to never put on tires that have a lower load rating than the original equipment tires. I'm not sure, but I think the OEM tires had a load rating of 93 = 1443 lbs. Obviously the SC comes now where near the load limit - it's a safety thing.

The link I posted below has a good discussion on how much pressure is needed when changing tire size - in addition to the pressure calculator.

One final note. Obviously, a minimum would be to have 4 tires whose combined load rating exceeds the GVWR (Gross Vehicle Weight Rating - includes car, passengers, packages, fuel, fluids, etc.). For my model the GVWR is 4530lbs. The SC430 has a 53/47 percent front/rear weight distribution. So, the front tires should have a very minimum load rating that meets/exceeds 2400 lbs. That would be a number equal to or exceeding 87 (see my early comment about OEM I think being 93 for safety).

 

Thanks all for your input. I'll put 36psi all around and see how she handles.
Chris.....From OZ.