K-A

Recently looked up the recommended pressure for a 991.1 with 20's, which appears to be 31/39 (normal load). Since I got my car, it's been at about 35-36/38-39 (cold). Didn't realize I was so over on the fronts, and wondering if there's any reason for that, or what you guys are running.

My car's a C2 on HRE 20's which are lighter than stock (not sure if that affects tire pressure?) and 305's out back.

Any benefits to having them higher or lower than stock, or to keeping the OEM recommended 8 PSI difference between rear and front (mine is clearly less than that)?

STG

Comfort: Tire pressures 31F/34R cold -- 33/36 hot

Many wise Rennlisters on here once recommended these and have worked for me. OEM tends to be higher based on playing it safe with higher weight loads (multiple people, frunk full, etc).

Weight of the wheels have nothing to do with it. Pressure is pressure and based on whatever weight the overall car is they’re sitting on.

As an FYI, I have 20” forged HRE’s

Al.Fresco

I'm a 32/35 guy....about a lb over recommended comfort/partial load setting.

K-A

Looks like I'm well over you guys. I guess I'll play with it. I tend to like my pressures higher (improved MPG or whatnot), but on a sports car, I'm wondering if I'm sacrificing some comfort.

Al.Fresco

You will notice a somewhat less jarring ride with reduced rear pressures. Keep in mind however, when running at comfort pressures, when you get her up to about 165, a warning light will come on telling you that you need more tire pressure to safely push beyond that speed.

LexVan

Really hard maintaining good tires pressures this time of the year, when I do a few fall-color roadtrips, with the huge temp swings from early morning lows of 40's to daytime highs in the 70s or even 80s.

For the most part I run 34/38 on 20" 245/305 MPSS.

In the dead of the summer heat, I keep the rears to stay below 40 hot.

Interesting note from yesterday's roadtrip. Driving along, all good, then hit some light rain, bam, the tires dropped 2 PSI from the cooling effect of the rain.

Porsche_nuts

You actually took you car out in the rain??!! LOL

LexVan

1,000 miles in 2.5 days. I can't control everything.

I had the car polished and CQuartz Pro'd about a week about. After the first day and over 300 miles of back roads, the entire front end was bloody bug coated. It rained a little overnight at my hotel. 90% of the bugs washed off (bugs can't stick to the nano coating and a little H2O). I was very pleased.

Oil change Thursday (another 6,000 miles since early July).

Then 2 more road trips (WI fall color, then MO wine country and fall color). Probably another 2,000 miles.

Take the car apart. Wash and detail. Put back together. Cover. Start again March 2018.

I'll do about 14K miles this season, all said and done.

cajerseyboy

Interested. Are you removing the wheels and bumpers when you do your winter prep cleaning?

Dewinator

Once you get used to comfort, you'll be like what is wrong why is the car riding so terribly when the dealer pumps you back up to full load.

4pipes

I uncheck full load and comfort. Right now that yields 32/38.

LexVan

Just the wheels. I clean everything I can see and reach in the wheel wells, and then Optimum Gloss Coat the wheels and calipers.

My MasterBlaster and shop vac does a great job keeping the front rads clean. I may repaint the center rad (PowerKit) again this year. I did that two years ago. Super easy. About 30 minutes of taping off stuff and 45 seconds of semi gloss black paint. Gives me someting car related to do in the heated garage during the holiday break.

okbarnett

I keep my cars at 35-38 cold, and never let them go lower

K-A

Interesting. That�s about where I�m currently at (I�m maybe a PSI air two higher). Why is that?

I should also add that I live in a warmer climate.

cajerseyboy

Ah the simple pleasures of a good car wash and detail in a finished garage. I can relate! Thanks. ( sorry OP for the hijack).