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Discussion Starter #1
Hey it's summer time and I put some BFGoodrich Sport Comp 2s on my 2012 Chevy Cruze with 235/45ZR18 98W, and I was wondering what tire pressure I should be running? I have 35PSI in them right now and while they do handle good with that amount I would just like some extra clarification and/or suggestions.

Thank you
 

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Find the pressure you like between the door placard pressure and the max sidewall pressure. Radial tires don't bulge from extra pressure as long as you remain at or below the max sidewall pressure. Remember to check your tires cold and that there can be as much as a 5-7 PSI difference between morning and afternoon pressures.
 

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The door post pressure is geared around a balance of ride quality, tread life, and rolling resistance.

In your case, 35 psi is the target pressure for the chassis regardless of tire used.......but you get to experiment.

The tire sidewall will have a Maximum Cold Pressure stamped on the sidewall.

You can safely operate at any pressure between the door post recommendation (35 psi) and the max sidewall psi.

I think your cold tire max on the sidewall is 44psi......if I'm right you have 9 psi to play around with.

Another example.....those of us with a Eco running fuel max tires....also door post recommended pressure 35psi.
These tire have a max cold sidewall pressure of 51 psi.
So, in this case, anything from 35 to 51 psi is acceptable.....the positives being potentally better fuel mileage and tire life, the negative being a bit harsher ride on small imperfections and potentally less available traction since the tire footprint is slightly shorter measured from front to rear.

So, go ahead and experiment in the range you have to work with.....the correct pressure is where you like the way it drives.

EZ PZ,
Rob
 

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Discussion Starter #4
Find the pressure you like between the door placard pressure and the max sidewall pressure. Radial tires don't bulge from extra pressure as long as you remain at or below the max sidewall pressure. Remember to check your tires cold and that there can be as much as a 5-7 PSI difference between morning and afternoon pressures.
My understanding is if I set it to 38 psi cold and it raises to 45-46 when the weather gets hot and more when the tires warm up completely that even though its over the 44 Max PSI it doesn't mean you need to lower it right?
 

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Discussion Starter #5
The door post pressure is geared around a balance of ride quality, tread life, and rolling resistance.

In your case, 35 psi is the target pressure for the chassis regardless of tire used.......but you get to experiment.

The tire sidewall will have a Maximum Cold Pressure stamped on the sidewall.

You can safely operate at any pressure between the door post recommendation (35 psi) and the max sidewall psi.

I think your cold tire max on the sidewall is 44psi......if I'm right you have 9 psi to play around with.

Another example.....those of us with a Eco running fuel max tires....also door post recommended pressure 35psi.
These tire have a max cold sidewall pressure of 51 psi.
So, in this case, anything from 35 to 51 psi is acceptable.....the positives being potentally better fuel mileage and tire life, the negative being a bit harsher ride on small imperfections and potentally less available traction since the tire footprint is slightly shorter measured from front to rear.

So, go ahead and experiment in the range you have to work with.....the correct pressure is where you like the way it drives.

EZ PZ,
Rob
Thank you, I was typing up my last reply as you posted this one and you've given me a lot of useful information.
 

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My understanding is if I set it to 38 psi cold and it raises to 45-46 when the weather gets hot and more when the tires warm up completely that even though its over the 44 Max PSI it doesn't mean you need to lower it right?
I target my tires to be 50 PSI when I get in my car to drive home from work. The car has been sitting in the sun all day so I look at the side of the car in the shade. In the mornings they're usually sitting around 46 PSI. What I discovered is that the maximum pressure seen from either 46 or 50 PSI is around 53-54 PSI, which while over the sidewall pressure is ok because the sidewall pressure is "cold" pressure. What I don't know is if cold means morning cold or afternoon cold.

Also, check your tires at least monthly as you will need to adjust their pressure simply from normal temperature swings as the seasons change.

Note: ECO MT running 51 PSI LRR tires.
 

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My understanding is if I set it to 38 psi cold and it raises to 45-46 when the weather gets hot and more when the tires warm up completely that even though its over the 44 Max PSI it doesn't mean you need to lower it right?
Well, just to clarify, don't be concerned about hot, operating temperature......just be concerned with the cold (approx 12 hours of non use) pressure.
The tire manufacturer has designed the tires capabilities around a far higher pressure than you would ever see 'hot'.

I keep my Cruze at 50 psi cold.....on the highway, after an hour or so, hot summer (95 deg) I'll usually show 54/55 psi.....well within any tires pressure capabilities.

Rob
 

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Discussion Starter #8
Ok that's good to know! Thank you, I appreciate all the info I know a lot of people just throw pressure in their tires but I like to know the ins and outs of everything :D
 

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As you increase pressure the ride will stiffen. The flip side of this is that cornering will become more predictable because there will be less flex in the sidewalls. You'll also see a slight improvement in fuel economy on the open road - again, less sidewall flex, and very likely longer tread life, once again, less sidewall flex. Sidewall flex is the major source of heat build up in the tire while driving.
 

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FWIW, I used to keep my Fuel Max tires between 40-44 psi and averaged 42 mpg for 70,000 miles.
I now have my General Altimax RT43's at 38-39 psi and have dropped my mpg average to 38. However I like the ride and handling much better since at 35 psi they were too comfy and squirmy to me.
 

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I just got the Rt43's put on two days ago. I think the garage put 42 in the rear and 40 in the front. or vice versa. But am going to even them all out and make them all 40 , then try 38 , then try 35. Cant wait! They are SO AGILE compared to the fr710's 5 years old with 53,000 miles from factory. Even at 42 psi, they are about as soft as the fr710s at 35!!! LOVE these tires. Not used to turning so fast though. Before at highway speed (55) I would turn and it would slowly catch up but now they TURN FAST! little scary at first lol. When I say turn, these brand new rt43's TURN!
 
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