tyre pressure in 17"

[S3SR]

i did search but all i found was a whole heap of numbers

ok i bought BA SR 17" rims fitted today, one looked abit flat so i went to inflate...im use to 35psi in my 16"s so i went for that in the 17's.....they just started deflating and look flat. so i inflated to 40 and thats more than what most people have said they use????? : to top it off the rear one was set to inflate to 40psi, but started deflating down and looked flat... im lost

anyways tyres are 225/50? 17" what should i be using for max tread wear and best fuel econ and best comfort .... that'll trick ya

pics in my workshop thread soon..

thanks heaps

[AU dude]

Just because it looks flat doesnt mean it is flat, from the other pics of your tyres and rims you show in the other thread, looks like you have a tendency to over inflate tyres.

It looks flat because of the profile of the tyre i assume, if the rims are 17x8 then 225/50 are the wrong tyres for that type of rim, the correct tyre is 235/45, unless you are using a smaller tyre so it is stretched over the rim, this gives better steering response, not sure about wear though.

Try no more than 36psi. i run 34 psi all round on my 235/45 tyres

[Chippar]

I think I'd be getting another tyre pressure gauge. I run 260Kpa (37.6psi) in my 16's and found that to perfect for me and I would assume that it'd be pretty good for the 17" as well.

As I said, if you have to deflate them to 40psi and they look flat, then I'd be looking for another gauge, even if it's only to make a comparison between the two.

[AU dude]

Do you go to a servo to check/adjust tyre pressures? because most of them have been drop 100 times and once they are dropped they give faulty readings...

[phildee]

I always run 40psi in 235/45 17's

I've been told 38 - 42psi for good handling/wear

[The Monty]

I put in 40 in the front, 36-38 in the rear. I only use the digital ones at the srevo, and yes I do realise that they can be out just as much as others, but meh.

[fordAU]

I tend to run with 40 all round on 17's, have done so for years with no issues and good even tyre wear.

No idea if that tyre pressure is optimum but it works for me.

[S3SR]

Originally Posted by AU dude

Do you go to a servo to check/adjust tyre pressures? because most of them have been drop 100 times and once they are dropped they give faulty readings...

i use the one where you select pressure on the screen thing and all that can be dropped is the hose.

ill check the pressures tomorrow, theres a few servos in a row

[GK]

Originally Posted by FALCONSR

i use the one where you select pressure on the screen thing and all that can be dropped is the hose.

ill check the pressures tomorrow, theres a few servos in a row

If you use those, use it twice per wheel. I find that they are generally 1psi off what they are supposed to be. For example, if I want 36 psi, I ask for 37 psi at the machine. I also find that if you put the machine on again after the beeps have concluded, the machine will read 1 psi lower than what you inputted into the machine.

Hope all that made sense, did to me anyhow! LOL!

GK

[AUXRVIII]

Any car I've ever owned regardless of tyre size I've run a minimum of 36psi.

[Hords]

I had my front 17x235x45 SP3000s replaced recently (Bob Jane) and was told 34psi was the best pressure for least wear. I also carry a pressure gauge. Even the digital inflaters can be out as much as 4 psi. Bet you they're not calibrated as frequently as what they're meant to be.

[JC]

This should really be in the wheel/tyre section, and a search there would have netted you the answer. The answer according to the tyre experts is 38 minimum, 39 ideal, 40 if open highway high speed cruising (that's 100/110), or if towing.

34 will see the edges wear out before the centre section, which falcons tend to do anyway, so a higher pressure will help stop that happening.

Just for the record, ideal pressures are as follows:
15 or 16" 36 PSI "normal" driving, up to 37/39 for highway use
17" 38 PSI normal, 40 highway
18" 40PSI normal, 41/42 highway.

These pressures give you the best tyre contact patch on the road, while evening out the wear across the whole contact patch.

[AK]

40 psi for me too.

[ForteAU]

i run 36 - 38 in my 17"