I have a 2011 Infiniti g37 sedan with michilene premium sports tires stock size. I was wondering what would be the best psi to set my tires to for best launches on the street. I have lowered my car like a inch if that makes a difference. My friend said to do a little more psi in the back than the front. What do you guys think? Weather is around 40 degrees.

 

Read the manual.

 

Read PongSanity's post

 

lol. these posts.

 

Good info right here

 

I have stock size 225/50-18s on my xS anniversary stock wheels, my door sticker says 33 all around, and I run about 35 or 36 all around.

 

2011 sport and i run 34 in the summer and bump 1-2 in the winter month here in FL

 

yes...helpful aren't they

The number in the manual & the door sill are the "recommended" pressure for best fuel economy & ride...

Your actual PSI should be adjusted for your weather/roads/tire brand/size & desired ride quailty. As long as you don't go over the max cold PSI stamped on the tire you can adjust them to whatever.

Start at the stock spec & try 5 psi above it...see if the car reacts better for you. Generally higher PSI will increase your road contact patch & enhance the performance of the car...but it may give up some fuel economy & increase ride harshness. Also be careful if you go too high you will have bad tire wear.
There is no magic PSI IMHO.You have to adjust for the factors I indicated & keep a schedule to check & adjust.

 

Good information. I thought it was lower psi for performance. Ive seen where people go to the track and they say to lower psi. Guess there is a difference from track and street? I have read to increase psi to improve mpg.

 

Depends what kind of track~dragstrip or road coarse. Some get better drag times w/ lower psi.

 

Lowering PSI for increasing performance on the drag strip does not become a factor unless you're running very high horsepower and drag slicks. In our case for the street, it's more about the tire compound makeup than pressure. A softer compound will generally grip better and high-mileage harder compounds. Most of us here when we're going to the track are on standard radials. For our cars, you don't want the pressure too low because the rolling resistance increases as pressure decreases. That will definitely impact trap speed as well as your time.

In top fuel drag, the tire pressure is lower because it allows the tire to wrinkle up around the wheel. It absorbs some of the full force from the engine so the tires don't completely break loose and in essence functions a little bit like a second clutch.

Look at his video as an example:

 

It's actually the opposite. Higher pressure in the front to reduce rolling resistance, since this is a RWD car. On the rear, a lower pressure than the front is better but it should not be too low to create rolling resistance.

Summary:

Higher in the front (~32psi)
Lower in rear (~26-28psi)

This is just for the track launch. I haven't tried this, but will be testing it out next time at the track.