hello I looked for this already in old posts but couldn't find the answer, so... What pressure is best for 225/40/18 tyres on a MkIV Golf ? PSI would be useful as that's what my local petrol station display uses ! I know its a basic question, but I'm NEW, hurray !
fuel cap has pressures for 15" wheels, but thought it would be different for low profile 18's, or is it the same ? Sidewalls just say max 44 psi, I guess the pressure will depend on car they fit onto. Anyone running 18's, what's yours at ?
The pressure wont remain the same as there is less space internally for the air to fill out as the rims are larger and the tyres smaller. 30psi in large sidewall, big bouncy tyres is all well and good, if you put 30psi in smaller sidewall tyres it will be under inflated and the wear will suffer as well as the ride. Try 34 front and 36 rear and I guarantee you will be very impressed by the improved handling and response. As the Mk4 is heavier than the A3/S3 also perhaps experiment with 36 front 38 rear. These settings are in common use within the S3 crowd and are recognised as excellent and improve the car no end.
on a mk 4 golf u should only use 34psi in the front and 32psi in the rear or else u come into all sorts of handling problems and also tyre expectancy will be short lived
PSI is just that - pressure per sqaure inch - it should be the same regardless of tyre/wheel size and is related to the weight of the car. It's not a measure of the amount of air in the tyre, but the pressure in it - as gillm said.
noted, PSI is indeed a measure of pressure per square inch. However, exerting pressure on the outside of a massive flexible chamber filled with air at a total pressure of 32psi will give different results to a tiny flexible chamber filled with 32psi. You cannot apply lab conditions to tyres due to the fact the actual construction of the chamber itself has an effect outside of the pressure inside. In a lab situation both chambers filled to 32psi would react in exactly the same way, this is just not true when you now have to take into consideration sidewall strength, resistance to deforming when exerting pressure on one edge, etc etc. This is even shown on the pressure info on the walls in garages, if you look at a manufacturer that does small skinny tyres, and on the same model also does large wide tyres, quoted pressures will be different! Hence a lot of people of have been experimenting and general consensus is that 34 front, 36 rear has reliably turned out to be the best.
Thanks for the replies, I am no scientist but do believe the ideal pressure will be different depending on profile. I don't want the tyres to flex as much as larger side walls otherwise my rims will be knackered due to this country's lovely road surface quality ! I will experiment with 32 - 36 (more at the front as thats where the engine is) and see how it goes.
Anyone got optimum tyre pressures for the mk2 golf gti running on 195/50 toyo's. Ive got it set at about 30psi at the moment. Cheers Wahid.
Hey cool, I can answer my own question... kind of ! Kona, my MkII ran on 195/50/15 and was great at 29-30 front, 27 back (average sized bass box in boot weighed a fair bit). Tyre wear was even and lasted as long as expected, plus the grip level was very good (BF Goodrich).
Cherrs mate will give it ago. my car doesnt have anything in the boot so should i use a lower or a higher pressure on the rears??
You could go lower, but I would try 26-27 even without the box. The sub box and amps weighed less than a fully grown fella. Handbooks always advise to put more air in if you are fully loaded. How are the toyo's? Are they Proxes? I have Khumo (cheap ones that came with new wheels), they look nice, but not convinced about the grip, hence my question about pressure. If I get this right they might get better. Almost went for Proxes.
Cheers mate. They're Toyo Proxes T1-R's allround and they seem to doing their job nicely. Here's some pics: http://www.clubgti.com/forum/showthread.php?t=87573 and on second page. Got any pics of your dub? What do ya think??
2 beauties there mate, love the wheels on both of em! I had a Royal Blue 8 valve which I loved for 6 years or so until it met the rear end of an audi quattro that pulled out in front of me quickly, but not quick enough. I have only a couple of pics but don't have them on a website at the moment. I have a blue MkIV turbo now after a short while with a Saab 900 ( I can explain!! ). Love the IV, but also really miss the MkII. I was just about to go 9x16 Brock, and was devistated when it went wrong....anyway, take care of the MkII, she looks a good un !
