Jump to content


Show
Photo
- - - - -

Tire Pressure


  • Please log in to reply
5 replies to this topic

#1 Hjalle

Hjalle

    Feet Under The Table

  • Budding Enthusiast
  • PipPipPipPip
  • 126 posts
  • Name: Hjalmar
  • Ford Model: Ford Fiesta mk6.5
  • Year: 2006
  • Location: Other / Non-UK

Posted 10 March 2014 - 12:26 PM

I recently had my Fiesta in for a service at an independent garage where I got them to do a tire check and rotate for me as well, the garage I used put a sticker on the windscreen recommending 34PSI all around.

 

When I checked the pressure on Saturday night I saw I was running 35PSI. I thought all of this sounded very high and upon checking Ford suggest 31PSI front 29PSI back on 195-45-16 84W tires.

 

I let the pressure down to the Ford recommended pressure and have found my ride to be less crashy - does anyone have any idea why they would have me running such a high PSI and what do you run? Higher, lower or recommended pressure?



Have something to contribute?

Sign in or register to start a topic...

Sign up to FOC Premium Membership To Remove These Ads

#2 D13 HPD 95

D13 HPD 95

    Ford Enthusiast

  • FOC Supporters
  • 1,582 posts
  • Name: Daniel
  • Ford Model: Fiesta mk7 1.25
  • Year: 2009
  • Location: Norfolk
Contributor

Posted 10 March 2014 - 12:34 PM

i run 31-34 psi but if i have a heavy boot which i do some weeks ill put 38 in the rears i was told 32psi from a ford garage but the manual and the haynes manual says different



#3 Stoney871

Stoney871

    Resident Peacekeeper

  • Super Mod
  • 14,076 posts
  • Name: Clive
  • Ford Model: Focus mk2 1.8 TDCI Sport
  • Year: 2007
  • Location: Devon
Contributor

Posted 10 March 2014 - 01:51 PM

All our work cars (Focus) have a 31psi label on the wheel arches.

#4 FOCA

FOCA

    Feet on the table

  • True Ford Enthusiast
  • PipPipPipPipPip
  • 2,538 posts
  • Name: FOCA
  • Ford Model: Mondeo Mk3 Sleeper 194 flb.p.t.
  • Year: Non
  • Location: Scotland
Contributor

Posted 10 March 2014 - 03:55 PM

I run 39psi in the front and 41 on the back, the higher pressures reduce friction/ drag so you should get a (slightly) higher MPG,

 

the higher pressures protect your wheel rims/ alloys

 

I like the direct feel with these pressures, the steering response is quicker i get more grip in wet/ cold conditions (because i get more heat into the tyres) and get quicker feedback when the car is about to "let go" - if i have a slow puncture and one of my tyres is down just a few PSI -i can feel it immedeately

 

With the (realatively) high front tyre pressures, the steering is lighter at parking speeds, so it gives the power steering an easier time, in snow/ ice, i can feel when the car is about to slide, sooner than with lower pressures

 

if you corner very hard, the higher pressures stop your tyre sidewalls from deflecting, if you drive mostly on twisty roads and corner hard(ish) even if you use very high pressures you will not wear the middlmiddle of your tyres out, you will wear the "shoulders" out 1st , if you do a lot of motorway / straight line driving, you will wear the middle of the tread out faster (with "too high" a pressure) - so the wear on the tyre is a good indication of the pressures you should run - if you are running very high pressures and you are still wearing your front shoulder/s tread out (FWD car) you probably need to slow down a little on the bends

 

"back in the day" a car would have 2 sets of pressures, higher ones fior "high speed/ heavily laden" and lower ones for "normal" driving (read- your gran going down to the shops- if that is "normal" for you)

 

Tyre pressures are only "recommendations" you should try different pressures (within the tyres maximum limit) to see what is right for you - it took me a long time to find the ideal 39-41PSI for me/ on my car - yes the ride is harsher - we ex race drivers have had heated discussions about the best pressures to run - but 29psi is for comfort (gran going down to the shops) - not grip/ handling or getting that extra MPG

 

PS - that (OPs) Fiesta desperately needs de-tangoed Image1.gif

 

 jUST to add, diesel engined cars engines can be very heavy, so a high front PSI is often required, (Mondeo MK3 2.0L diesel 41pst recommended in the front wheels ) even with this high pressure, the tyres can look underinflated - if it looks underinflated, it probably IS underinflated - if you increase the PSI in the front, you should do the backs too, as you may get lift-off oversteer if your rears are softer than your fronts  



#5 Hjalle

Hjalle

    Feet Under The Table

  • Budding Enthusiast
  • PipPipPipPip
  • 126 posts
  • Name: Hjalmar
  • Ford Model: Ford Fiesta mk6.5
  • Year: 2006
  • Location: Other / Non-UK

Posted 14 March 2014 - 01:44 PM

Ah ha I see, after having had the lower pressure for the past couple of days and felt it nice to be comfortably wallowed around the pothole ridden roads by me, I am starting to get over it and notice that it doesn't suit my teenage male driving style and as you said FOCA the steering is heaver when in city driving which is kind of annoying. 

 

I also phoned the garage up today and asked and the gentleman on the phone said that Ford recommend the lower pressure for the comfort of grandma's but with my tires they run squarer, give better performance and wear more evenly when run at 34PSI

 

So Ive put the pressure back in and am much happier, as driving pleasure comes before comfort



#6 LightningMat

LightningMat

    Car Nut !

  • Budding Enthusiast
  • PipPipPipPip
  • 132 posts
  • Name: Mat
  • Ford Model: 2014 Candy Blue Fiesta Zetec S 1.0t
  • Year: 2014
  • Location: Berkshire

Posted 16 March 2014 - 12:52 AM

Tyre pressures are a bit of a personal thing, but the key aspect for a normal road car is even tyre wear. Too low and both edges will wear out, too high and the middle will wear.

If just one of the edges is wearing out, then this is most likely a sign that the geometry is incorrect for the type of driving you are doing, and you should get this checked.

In an ideal world, you would adjust your tyre pressures to suit the roads and type of driving you are doing, but in reality, nobody is going to do that on a road car! So, as a compromise, the best advise is to find a happy medium (using even tyre wear as an indicator) and stick to that (although perhaps adjusting for winter / summer if you really want to).

1.0 125 Zetec S on order!

Have something to contribute?

Sign in or register to start a topic...


Not what you're looking for?

Register now, we have a huge community of enthusiasts to answer any questions you might have



0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users