18" tyre pressures? - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
Ford Forum Ford Forum

» Auto Insurance
» Featured Product
» Wheel & Tire Center

Go Back   Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > The Garage - Tech Forums > Suspension | Wheels&Tires | Brakes
Register Home Forum Active Topics Photo Gallery Auto Loans Garage Mark Forums Read Auto EscrowInsurance

Suspension | Wheels&Tires | Brakes Sponsored by: Discount Tire Direct

FordForums.com is the premier Ford Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 10-02-2003, 04:36   #1 (permalink)
Registered User
 
Join Date: Jul 2003
Location: Brisbane
Posts: 118
18" tyre pressures?

225/40 and 255/35 ZR 18 Falken tyres on an AU.

What tyre pressure should these be run at for normal street driving?

Thanks!
Q777 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 10-06-2003, 04:23   #2 (permalink)
NB & NCII V8 Fairlanes
 
Join Date: Feb 2001
Location: Bibra Lake Western Australia
Posts: 2,816
Re: 18" tyre pressures?

Same as any tyre per decal in the car.
__________________
Regards Blue
Aussiblue is offline   Reply With Quote
Old 10-06-2003, 05:03   #3 (permalink)
Bourbon powered V8
 
JC-XR8's Avatar
 
Join Date: Sep 2002
Location: Canberra, Australia.
Posts: 4,787
Re: 18" tyre pressures?

I run my 235/45/17s at 38 front and 36 rear in winter, and 40 front and 37/38 rear in summer. This helps reduce the uneven wear on the tyres. I would guess with 18s, you would want to run about the same (ie around the high30s to 40psi).
__________________
__________________________


AU1 XR8 Auto 147.9 rwkw (approx 215 fwkw)

AU2 Wagon HAD Auto
17s, Pacemakers, 3" Intake & Pod filter (The Family Hack)

Member of:
FPV-XR Club ACT
AUFalcon.com
ATPS (honorary)
JC-XR8 is offline   Reply With Quote
Old 10-06-2003, 05:18   #4 (permalink)
Registered User
 
Join Date: Jul 2003
Location: Brisbane
Posts: 118
Re: 18" tyre pressures?

Blue - my tyre decal doesn't list non-factory sizes...

JC - That high? Wow, I currently have 35 in them and was hoping to hear somewhere around the low 30s. Oh well, I'll go and add a few pounds. Thanks!
__________________
Cobra YS-Vortech, 74/28 cog, 24"x12"x4.5" intercooler, SVO N-351 block, SVO A-410 crank, Crower 6.25" billet rods, JE 8.5:1 pistons, 96lb/hr's, 90mm Accufab, MoTeC M800 sequential, MSD Digital 6, Powerglide, 35 spline 9", 17x11" Racing Harts.

XY Fairmont 460, Powerglide, 31 spline 9"

AU111 XLS 5.0 V8 Ute - 18x9" wheels 255/35/18 Falkens

Q777 is offline   Reply With Quote
Old 10-06-2003, 05:28   #5 (permalink)
Registered User
 
philstoj's Avatar
 
Join Date: Oct 2002
Location: Melbourne
Age: 41
Posts: 1,350
Re: 18" tyre pressures?

40 psi for the 18's,thats what i was told by the tyre dealer for my 18's..
__________________
Terrorising a crap driver near you!
philstoj is offline   Reply With Quote
Old 10-07-2003, 17:45   #6 (permalink)
Lamahs approve of manuals
 
Join Date: Mar 2003
Location: Sydney, Australia
Age: 36
Posts: 1,382
Re: 18" tyre pressures?

Out of curiosity, what does ford recommend for the factory 18's on the BA ? I've always been told run 38 or so in the 17's i've got, but it'll be interesting to see what the factory reckons

Last edited by XR8 Lamah; 10-07-2003 at 17:47.
XR8 Lamah is offline   Reply With Quote
Old 10-07-2003, 18:29   #7 (permalink)
FPV Tasmania Member
 
TS50's Avatar
 
Join Date: Apr 2003
Location: Tasmania
Age: 55
Posts: 961
Re: 18" tyre pressures?

For 18's the factory says
30 front / 30 rear for normal load
35 front / 39 rear for max load.
At that the edges of my tyres were wearing badly (sign of under inflation) My tyre guy suggested 36 to 38
I now run 38 all round
__________________
2002 Narooma Blue Manual TS50
Sunroof
TS50 is offline   Reply With Quote
Old 10-07-2003, 20:12   #8 (permalink)
Can't wait for Winton...
 
outback_ute's Avatar
 
Join Date: Jul 2003
Location: Victoria
Posts: 2,759
Re: 18" tyre pressures?

I never take too much notice of the factory decal as they’re always to low to make the ride nice & soft
outback_ute is offline   Reply With Quote
Old 11-07-2003, 15:46   #9 (permalink)
Registered User
 
Tominator's Avatar
 
Join Date: Nov 2003
Location: New Baden, IL. USA!
Age: 59
Posts: 22
Wink Re: 18" tyre pressures?

Quote:
Originally Posted by Q777
225/40 and 255/35 ZR 18 Falken tyres on an AU.

What tyre pressure should these be run at for normal street driving?

Thanks!
My first post!

When I purchased tires for my lowered '95 Ranger, I called nearly everyone in the tire business that I knew. There is no easy answer.

My own experience with this subject, been doing the car thing since '72, and never getting anything but standard responses from those that I thought should know, caused me to developed my own theories.

In the past and with older tire designs one usually obeyed the 'door sticker.' I've come to believe that this pressure is only for OEM tires the same size or close to that size bought from aftermarket suppliers.

It is the load ratings that are the limitation on safe pressures in regards to tire design!

A tire that has a max load rating achieved at say 40psi for example and is used at 30psi if a 'door sticker' is to be believed, has a decrease in that load rating of 1/4 of it's max rating. Now I'm sure this is on a curve of some kind as the load rating at 20psi might be only 1/5 of the max. but the numbers will suffice for this discussion.

The Sumitomo HZR IIIs on my Ranger have a max pressure of 51psi. I cannot remember the load rating and am too lazy to go out there and look, but that load rating is achieved at 51psi. Reduce the pressure and you reduce the load the tire can safely carry.

Given this a tire that has a higher max pressure should be run at a higher pressure than a tire with a lower max pressure and all this is tied to the maximum load capacity of the tire.

Throw in the actual load the car or truck puts on each tire, and this might vary considerably, and you've only begun to reason the answer to the question. The combinations are nearly endless!

Every axle must me independently evaluated as to the load it will carry and the PSI is the only variable the mechanic/driver can influence.

Now, after all that, I run mine at 40psi because I get a darn headache just thinking about this!

BTW, FIRST CLASS FORUMS!
Tominator is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > The Garage - Tech Forums > Suspension | Wheels&Tires | Brakes



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
No spare tyre for BAII ??? falconS Australian Falcons 33 09-01-2003 06:07
BA XR6 Tyre Pressures XR6 Uterous Australian Falcons 4 03-06-2003 23:47
18" tyre prices?? younggun General Tech 16 01-08-2003 13:40
Pirelli tyre article Falchoon The Pub 4 06-21-2002 03:20
New F1 tyre Falchoon Ford Racing Across the Globe 2 02-19-2002 11:01

Powered by vBadvanced CMPS v3.2.2

All times are GMT -7. The time now is 12:30.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.6.0
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.