What a difference. I couldn't believe it would make this much of a difference. It was feeling squishy and just 'wrong'- I had the front and back at about 28. Now 32 and 35 and it feels like a different car. The back feels higher and tighter and as if when I steer the car is going the direction I want it to.

 

I had done a search and it seems I'm not the only one who had been using the wrong pressures. Just couldn't believe one simple thing could make it feel so different driving.

what can i say? Do imports not have the tyre pressures listed inside the cubby box in the center console? if they have ? do you never open it or only with your eyes shut! not being sarcastic mate but the pressures are listed in the handbook and if u werent sure you could have rung a garage. Wel now they are right time for FUN !!!!!!!!!!!!!!!!!!!!!!

the tyre pressures are listed inside the drivers door, the cubby hole seems a strange place to put them seeing as a lot of Zs dont even have the cubby hole.

Maybe I'm just a slacker. I kept them as they came to me from the alloy place. I have an import, but they gave me a nice new UK zed handbook and I can't find the pressures in it. My centre box does not have this sticker in it, but there is one on the door frame. But it's all in Japanese.

 

I didn't really think there was anything wrong- just a vague feeling it was not handling as well as it could. I don't ever look in that centre box really, and never with my eyes shut. My only consolation in being such a thick shit is that by the looks of quite a few previous posters, I'm not the only one who has got it wrong in the past. Does it make a difference that they are aftermarket wheels? i.e. 255s and 40 profile? If I had REALISED i was wrong about the pressure I would have called Goodyear and checked what pressure they should be or something. I would consider myself a very careful owner altogether- as I want to keep it good since it's only done 23K miles.

 

All I'm saying is a few lbs per quare inch really makes a difference. I would never have thought it would. But maybe 'a few pounds' isn't trivial. I am not an expert in the dynamics of wheels tyres and the effect it has on the car, so I'm glad I've got another bit of stupidity cleared up.

Whenever I do some trivial little bit of 'home maintenance', like fixing the broken alarm sensor clip or changing a wheel and it not actually falling off (you see- I do mean trivial) I get a sense of achievment/pride well out of proportion to the task. Even if it's pretty crap compared with guys removing the engine etc. I am in awe of people like my brother-in-law who owns and uses an engine stand and hoist.

Right up there with you Rich, I've a garage full of tools but still use a chisel to open cans of paint! I've serviced most of my funday cars but the Zed looks bit daunting.

 

Thanks for the tip on the tyre pressures - since I got new shocks she's handled really well, tomorrow I'll check the tyres - and see if I can eeekk another percentage point of G on the roundabouts. :)

Hey Rich,

yeah it does a make a difference if u dont have stock size wheels/tyres.

I have stock and run 32psi front and 35 psi back, coss it feels the best to me,

and tyres wear completely evenly, didnt even know that was the reccomended!

If you have 255/40's then the psi in the handbook means nothing.

Play around with them till they feel right, tho it sounds like they are now. :-)

Thats actually a very good point Rich - the Z is well know for its sensitivity to tyre pressures. You'd be amazed how many people fail to check their tyre pressures regularly, then blame it on the tyres being crap....

Surely most Zeds now have aftermarket alloys fitted so how is anyone to know the 'correct' pressures for the wheel/tyre combination they happen to have on their car?

 

Is there a way of finding out or is it just feel/guesswork?

 

 

 

 

 

 

Oh, my sticker is on the drivers door 'B' pillar.

I set mine as 32 front 34 rear but mines an import so has 225's all round....Most garages get the pressure wrong coz they assume all 300's are UK spec and the rear tyres are bigger on them so set the pressure wrong.....

Getting them right makes a world of difference.

I checked up on the Goodyear web site- it says you go by the car manufacturer, so tyre pressure should be the same as stock. So it says, anyway.

 

My door-sticker says 225/50 16inch should be 2.3 or 2.5 kg/cm2 Which is 32psi or 35. I am guessing the figures refer to back and front although because my Japanese is not very fluent, I'm not sure.

 

I still want to know if Goodyear are telling the truth- should I go by the car manufacturer's figures?

 

'Proper inflation is the single most important part of tyre care. The inflation pressure on the side of the tyre is the MAXIMUM operating pressure. It is not necessarily the right inflation for your vehicle. Always use the inflation recommended by the vehicle manufacturer.'

Rich, they are assuming your car is stock and u havn't changed the size of the wheels/ tyres when they state that. :-)

So if you have bigger/wider wheels, should the pressure be higher or lower? or is it just like you say, experimenting until it feels right? Is there some formula somewhere I should know about?

Hi,

 

With my stoke wheels I run with 40 PSi on rear and 37.5 PSI on the front. I have a good feeling now with these pressures.

On stock wheels thats too much at the front. Your wheels will wear out in the middle and I'll bet the steering is nice and light as well....

My front tyres wear is very regular. It depends on the tyre and the road. I have BF Goodrich and with low pressure, my Zed go straight on in the curves! I live in the Alps and raod coating is not very good and there are a maximum of curves, and this pressure I feel very good sensations!

If your front tyres are 225 50 16 then really they should be on 32 - 33 psi I understand what you mean about the understeer if the pressure is too low though.