I just bought a 2003 Ford Crown Victoria with sport package. It is similar to the P71 Police Interceptor model with stiffer springs, thicker anti-roll bars, etc. I checked the sticker on the door and found that Ford recommends 32 psi for the front tires and 35 psi for the rear tires. This is a conventional front-engine, rear-drive car. I was expecting to see 29-32 psi, and same pressure for both front and rear. I don’t understand the manufacturer would recommend higher pressure in the rear for a car that is a little heavier in the front.
Any ideas?
Oh, I am thinking of keeping both the front and rear at 32 psi.
The manufacturer of the vehicle ran tests on a track with different tires at different pressures to determine what worked best for handling, braking, ride, and tire life. So we must assume the engineers had a reason to recommend those tire pressures. Of course there’s nothing wrong with adjusting the pressures up or down a few PSI to achieve your custom ride/handling characteristics.
The lower tire pressure in the front may be partially to counteract the heavier front suspension parts with the sport package. Cars like this I would normally run about 35 or so all the way around.
Rear drive cars tend to oversteer. Higher tire pressure in the rear tires decreases oversteer. The average American prefers understeer. Ford wants the RWD drive Crown Vic to handle like a FWD.
That makes perfect sense. Since slight to moderate understeer is preferrable to oversteer, Crown Victoria with sport package would benefit from higher pressure in the rear for the average person. I would think the recommended tire pressure for the police department would probably be even. Thank you.
The only drawback (or benefit, depending on your point of view), is that a higher tire pressure in the back would tend to make it easier to slide the back end, or power steer it with the throttle, if the engine has enough HP for this.
Try 35/35 and see how you like it. Do not use 32/32, it’s not a good idea to underinflate tires. You’ll get slightly better mpgs with 35/35, too, over 32/35.
Is it possible that there are 2 different tires listed on the vehicle tire placard and the pressure recommendation is being mis-interpreted?
Tire Guides says that 2003 Crown Vic’s came with both P225/60R16’s at 32 psi front and rear, and P235/55R17’s at 35 psi front and rear. Is it possible there is a bit of confusion?
No, mine has 225/60/16, and I double and triple checked to make sure I read it right. The placard does not show the recommended pressure for 235/55/17.
I’m no tire pressure expert, but I think the Crown Vic’s weight distribution is 56 front/44 rear, so it may not be as front-heavy as some would believe.
As I tried to point out earlier, the pressure in the tires has to be able to handle the car loaded.
If you load up the trunk, this is potentially many hundreds of pounds, far back on the car. So, the tire pressure needs to be high enough to allow for this. Duh.