I have 205/45-17's (non runflat) the area I live in has crappy roads and I'm thinking of lowering the tire pressure. I currently run all 4 at 39 psi. Any suggestions on how low I can go and if it's even worth it? 2012 MCS I don't think I have the sport suspension, any way to tell by visual inspection? I couldn't imagine a stiffer ride. Thanks

 

Don't go below the tire pressures on the door sticker. Other than that, you're OK.

 

+1 check the door for the recommended tire pressure to run.

 

We have that tire size on a '12 MCS. If I recall correctly, the door sticker says 38psi, 40psi if going over 100mph..

 

you can try lower pressures, I would stay above 28-30, however if you are in a very hot location , your tires could overheat, The big picture you will find it makes very little difference in ride quality , It not gonna hurt to go around the block for a test , but weird tire wear could come into play along with reduced fuel economy( that's why they are 39 from the factory) and sloppy handling. Your TPMS's might not like it either! this is all IMHO

 

I've ran 34psi since 2008. Haven't had any issues other than a more forgiving ride.

 

The door sticker provides information based on the tires that were OEM at the time of sale. In this case, run-flats. That tire pressure is way too high for standard tires. I'm running mine at 35psi without any issues (all "good" pavement, though).

 

That's kind of what I was thinking. I lowered them down to 36 last night. I need to drive around more but I feel like that took a little bit of the edge off. I might drop it another one or two psi and see how that works out. I've had several sporty fwd coupes and can't recall ever filling the tires to 39 psi+ (non runflats)

 

You could lower the pressure from what you are running. 33 - 35 psi would be reasonable and it would make a noticeable but not huge difference. You do so at the increased risk of wheel damage if you hit a pothole with those 45-series tires, though. 16 inch wheels with a taller tire might be a better choice.

 

The tire pressure ratings on the door sticker are provided both for comfort and for handling. I freely grant that the run-flats usually ride like stones, but going lower than those pressures may trigger a low tire light and may hurt gas mileage. I wouldn't recommend it.

 

Yes, you will need to reset the tire pressure monitor when you lower the pressure. Easy enough to do. Your gas mileage will not suffer unless you're one of the people that tries to get 40mpg all the time (hard tires, rolled up windows, highest gear you can, etc).