| View previous topic :: View next topic |
| Author |
Message |
andyj
Joined: 08 Sep 2006
Posts: 2412
Location: up norf
|
 Posted: Fri Jan 12, 2007 23:40 Post subject: something fun about tyre pressures |
 |
|
evening chaps
got some new falken t110s fitted yesterday on the Deli, due to axle wind up using differing tyre sizes front and back
the guys in the tyre place (not a dodgy backstreet one) inflated all the tyres to 40 psi! turns out teh reason behind this is different tyres work at differing pressures, for example my old yokohamas were at 32 psi and ran fine....turns out newer tyres tend to work at higher pressures due to thicker walls and more sturdy construction
"just see what those look like at 32 psi"
so i tried :D .....they look deflated and very saggy
turns out old mitsi's 30psi spec for the Delica is only any worth on tyres produced about 10 years ago.
also found out a handy tip for off roading..... take the PSI down to about 15/20...and you get more grip and less chance of ripping your tyres on a rock, but if you go back on the road REINFLATE! otherwise the tyres might fly off the rim when your cornering 
they don't tell you that in the bloody misti manual! |
|
| Back to top |
|
 |
Google
Sponsor
|
| Posted: Fri Jan 12, 2007 23:40 Post subject: Google Ads keep this community free to join! |
|
|
|
|
| Back to top |
|
|
andyj
Joined: 08 Sep 2006
Posts: 2412
Location: up norf
|
| Posted: Fri Jan 12, 2007 23:41 Post subject: |
|
|
| max pressure on the t110s under load are 55psi if thats any use |
|
| Back to top |
|
|
mythatsabigun
Joined: 22 Dec 2004
Posts: 922
Location: South...West...(very)
|
| Posted: Mon Jan 15, 2007 0:38 Post subject: |
|
|
 oh blow!!!...I just 30 everything!!
_________________
Deli finally sold - don't ask :-(.......Me signing off, thanks for being such a brilliant forum, keep 'em going - May be back if I can start earning decent dollar again - take care y'all ;-) |
|
| Back to top |
|
|
mythatsabigun
Joined: 22 Dec 2004
Posts: 922
Location: South...West...(very)
|
| Posted: Mon Jan 15, 2007 0:39 Post subject: |
|
|
blow?!!? - ha, that's not what I typed!!
_________________
Deli finally sold - don't ask :-(.......Me signing off, thanks for being such a brilliant forum, keep 'em going - May be back if I can start earning decent dollar again - take care y'all ;-) |
|
| Back to top |
|
|
petemillis
Joined: 11 Mar 2004
Posts: 709
Location: Brighton, UK
|
| Posted: Mon Jan 15, 2007 19:42 Post subject: |
|
|
I'm also running pressures of 40 to 42psi in my Michelin Cross Terrain tyres and the ride and cornering are far far better. I'd tend to agree that for a bus weighing over 2 tonnes, on tyres with STIFF sidewalls and for on the road, pressures as low as 30psi are too low. I'd had problems with edges of the Bridgestone Duellers at 32psi wearing far quicker than the centre - and no, it wasn't a tracking issue as it was both edges of the tyres.
If anyone want to read more on tyre pressure then go to the Aussie Delica forum - you'll see a lot of owners are using 40 to 45psi.
Since running higher pressures my economy has also improved by a fair bit.
Pete Millis from Brighton
_________________
Pete
1995 Delica Space Gear Exceed (PE8W) in LaGuardia silver with chrome tints and BIG round things. |
|
| Back to top |
|
|
strangerover
Lifetime member
Joined: 17 Oct 2006
Posts: 4357
Location: Ashton-in-Makerfield
|
| Posted: Mon Jan 15, 2007 23:13 Post subject: |
|
|
Pete....
this has just happened to me with my duellers....
after reading this the other day checked my pressures...
30 psi..
now at 40 psi.... and what a difference... much better MPG ! and handling, and the tyres "look" right... will use 25psi off road still but for road 40-45psi
land rovers run higher pressure on the rear... would this be right on the Deli ?? about to do a very long tow should I stick more air in rear say 45psi and 40 in front ???
_________________
Regards
Mark |
|
| Back to top |
|
|
REDNECK
Joined: 18 Sep 2005
Posts: 1085
Location: Dorset
|
| Posted: Mon Jan 15, 2007 23:27 Post subject: |
|
|
All you need to know about tyres and pressures here
http://www.carbibles.com/tyre_bible.html
_________________
No Deli anymore, Mk2 Pajero instead, 2" suspension and body lift, 35's, twin winches etc |
|
| Back to top |
|
|
saint
Joined: 09 Sep 2004
Posts: 248
Location: Pembroke Dock
|
| Posted: Mon Jan 15, 2007 23:35 Post subject: tyres |
|
|
36 PSI 3YRS NO PROBS
_________________
just mad, no need for logs, I liked my axe. |
|
| Back to top |
|
|
petemillis
Joined: 11 Mar 2004
Posts: 709
Location: Brighton, UK
|
| Posted: Tue Jan 16, 2007 1:01 Post subject: |
|
|
Here's a quote from the link that Redneck just posted
| Quote: |
Tyre pressure and gas-mileage.
For the first two years of our new life in America, I'd take our Subaru for its service, and it would come back with the tyres pumped up to 40psi. Each time, I'd check the door pillar sticker which informed me that they should be 32psi front and 28psi rear, and let the air out to get to those values. Eventually, seeing odd tyre wear and getting fed up of doing this, I asked one of the mechanics "why do you always over-inflate the tyres?" I got a very long and technical response which basically indicated that Subaru are one of the manufacturers who've never really adjusted their recommended tyre pressures in line with new technology. It seems that the numbers they put in their manuals and door stickers are a little out of date. I'm a bit of a skeptic so I researched this on the Internet in some of the Impreza forums and chat rooms and it turns out to be true. So I pumped up the tyres to 40psi front and rear, as the garage had been doing, and as my research indicated. The result, of course, is a much stiffer ride. But the odd tyre wear has gone, and my gas-mileage has changed from a meagre 15.7mpg (U.S) to a slightly more respectable 20.32 mpg (U.S). That's with mostly stop-start in-town driving. Compare that to the official quoted Subaru figures of 21mpg (city) and 27mpg (freeway) and you'll see that by changing the tyre pressures to not match the manual and door sticker, I've basically achieved their quoted figures.
So what does this prove? Well for one it proves that tyre pressure is absolutely linked to your car's economy. I can get an extra 50 miles between fill-ups now. It also proves that it's worth researching things if you think something is a little odd. It does also add weight to the above motto about not trusting forecourt pressure gauges. Imagine if you're underfilling your tyres because of a dodgy pressure gauge - not only is it dangerous, but it's costing you at the pump too.
What's the "correct" tyre pressure?
How long is a piece of string?
Seriously though, you'll be more likely to get a sensible answer to the length of a piece of string than you will to the question of tyres pressures. Lets just say a good starting point is the pressure indicated in the owner's manual, or the sticker inside the driver's side door pillar.I say 'starting point' because on every car I've owned, I've ended up deviating from those figures for one reason or another. On my Subaru Impreza, as outlined above, I got much better gas mileage and no difference in tyre wear by increasing my pressures to 40psi. On my Honda Element, I cured the vague handling and outer-tyre-edge wear by increasing the pressures from the manufacturer-recommended 32/34psi front and rear respectively, to 37psi all round. On my Audi Coupe I cured some squirrelly braking problems by increasing the pressure at the front from 32psi to 36psi. On my really old VW Golf, I cured bad fuel economy and vague steering by increasing the pressures all-round to 33psi.
So what can you, dear reader, learn from my anecdotes? Not much really. It's pub-science. Ask ten Subaru Impreza owners what they run their tyres at and you'll get ten different answers. It depends on how they drive, what size wheels they have, what type of tyres they have, the required comfort vs. handling levels and so on and so forth. That's why I said the sticker in the door pillar is a good starting point. It's really up to you to search the internet and ask around for information specific to your car.
The Max. Pressure -10% theory.
Every tyre has a maximum inflation pressure stamped on the side somewhere. This is the maximum pressure the tyre can safely achieve under load. It is not the pressure you should inflate them to.
Having said this, I've given up using the door pillar sticker as my starting point and instead use the max.pressure-10% theory. According to the wags on many internet forums you can get the best performance by inflating them to 10% less than their recommended maximum pressure (the tyres, not the wags - they already haves inflated egos). It's a vague rule of thumb, and given that every car is different in weight and handling, it's a bit of a sledgehammer approach. But from my experience it does seem to provide a better starting point for adjusting tyre pressures. So to go back to my Subaru Impreza example, the maximum pressure on my Yokohama tyres is 44psi. 10% of that is 4.4, so 44-4.4=39.6psi which is about where I ended up. On my Element, the maximum pressure is 40psi so the 10% rule started me out at 36psi. I added one more to see what happened and it got better. Going up to 38psi and it definitely went off the boil, so for my vehicle and my driving style, 37psi on the Element was the sweet spot. |
Pete Millis from Brighton
_________________
Pete
1995 Delica Space Gear Exceed (PE8W) in LaGuardia silver with chrome tints and BIG round things. |
|
| Back to top |
|
|
spacecadet
Joined: 20 Aug 2005
Posts: 858
Location: winchester
|
| Posted: Tue Jan 16, 2007 22:39 Post subject: |
|
|
very good post about tyres. i run my a/t at 45 psi not sure if this is correct but seem to run o/k.
just need to get the alignment /tracking checked.as i have slight wear on one side 
also want to rotate mine but can't get the rear wheels off :? will have to get a tyre shop to do it 
_________________
...Dave... they called me mr square,
but i didn't really care,
until i bought a ( Space Gear)!!
i showed them i'm no fool,
now they call me mr cool!! |
|
| Back to top |
|
|
strangerover
Lifetime member
Joined: 17 Oct 2006
Posts: 4357
Location: Ashton-in-Makerfield
|
| Posted: Tue Jan 16, 2007 22:50 Post subject: |
|
|
use a bigger bar on the wheels....
I'm guessing they were put on with an impact air wrench.... (a knacker knacker gun)
As yet never found a wheel I could not get off by hand using a bigger lever or me standing on the end of the lever !
_________________
Regards
Mark |
|
| Back to top |
|
|
spacecadet
Joined: 20 Aug 2005
Posts: 858
Location: winchester
|
| Posted: Tue Jan 16, 2007 22:56 Post subject: |
|
|
i can get the wheel nuts undone but i can't safely pull the wheels off.
i have posted on this previously and was given a few suggestions on how to get them off,but to no avail.
i have even loosened the nuts and driven forwards and backwards to try and break them free.
_________________
...Dave... they called me mr square,
but i didn't really care,
until i bought a ( Space Gear)!!
i showed them i'm no fool,
now they call me mr cool!! |
|
| Back to top |
|
|
strangerover
Lifetime member
Joined: 17 Oct 2006
Posts: 4357
Location: Ashton-in-Makerfield
|
| Posted: Tue Jan 16, 2007 23:11 Post subject: |
|
|
have you tried undoing the bolts, have it on a axle stand and then kick the tyre HARD ? I use the sit on arse and use feet with big boots on..
it WILL come off thats all a tyre place will do, get the grunt in the bay to kick seven shades out of the tyre, you do not need to kick from behind just kick the tyre really really hard again and again and rotate a bit every so often and you will shock it off, there is no chance of you doing damage so long as its on a axle stand. I have worked on cars for many years and this has never failed me.
_________________
Regards
Mark |
|
| Back to top |
|
|
spacecadet
Joined: 20 Aug 2005
Posts: 858
Location: winchester
|
| Posted: Tue Jan 16, 2007 23:46 Post subject: |
|
|
have tried that,even used a sledge hammer. :?
i am spraying a lubricant around the hub trying to soak it free.
i haven't tried it again lately,just waiting for better weather and some more axle stands cos it kept wobbling when i was bashing six bells out of them before.
_________________
...Dave... they called me mr square,
but i didn't really care,
until i bought a ( Space Gear)!!
i showed them i'm no fool,
now they call me mr cool!! |
|
| Back to top |
|
|
ARCTIC FOX
Joined: 06 Mar 2005
Posts: 393
Location: BRISTOL
|
| Posted: Wed Jan 17, 2007 17:33 Post subject: |
|
|
I am using Pirelli scorpions 285x55xR18 what pressre should i be running at for these?
_________________
Kieron
SWB Super Exceed 2.8TD
6" Lift in Body (made good by Mark & Bruce)
W09 White & Naked,285x55xR18,Twin 4" Pipes |
|
| Back to top |
|
|
Lawe
Lifetime member
Joined: 28 Oct 2005
Posts: 528
Location: Irthlingborough, Northamptonshire
|
| Posted: Wed Jan 17, 2007 19:38 Post subject: |
|
|
What a top post this is!
I had mine set at 34/32 and that seemed okay.
However last night, this post had me going, so on the way home last night, pumped up the tyres to 40 all round.
What a difference The ride is so much smoother, just seems to glide along.
Now all I have to do is see what the MPG is like. |
|
| Back to top |
|
|
REDNECK
Joined: 18 Sep 2005
Posts: 1085
Location: Dorset
|
| Posted: Wed Jan 17, 2007 19:42 Post subject: |
|
|
It might also be worth carrying out an emergency brake test before and after raising the pressures, just to see if it's had a detrimental effect on grip 
_________________
No Deli anymore, Mk2 Pajero instead, 2" suspension and body lift, 35's, twin winches etc |
|
| Back to top |
|
|
Lawe
Lifetime member
Joined: 28 Oct 2005
Posts: 528
Location: Irthlingborough, Northamptonshire
|
| Posted: Wed Jan 17, 2007 19:51 Post subject: |
|
|
No probs there Mike!
Seems I may of had the "Deli Cloak" button on today. Daft  came straight out without looking. So brakes work very well! |
|
| Back to top |
|
|
Lawe
Lifetime member
Joined: 28 Oct 2005
Posts: 528
Location: Irthlingborough, Northamptonshire
|
| Posted: Wed Jan 17, 2007 19:52 Post subject: |
|
|
Oh and the horn... and my swear box has had it's fund topped up  |
|
| Back to top |
|
|
REDNECK
Joined: 18 Sep 2005
Posts: 1085
Location: Dorset
|
| Posted: Wed Jan 17, 2007 21:34 Post subject: |
|
|
| Lawe wrote: |
No probs there Mike!
Seems I may of had the "Deli Cloak" button on today. Daft came straight out without looking. So brakes work very well! |
Glad to hear you avoided the idiot
I thought the Deli probably would be okay with increased tyre pressures as it's such a heavy vehicle the tyre footprint is still good (see my previous link) but lighter cars can become very skittish on higher pressures or in fact on too wide a tyre. Contrary to popular belief (boy racers belief ) they can be what is termed "over tyred" in that the weight of the car is too light to make the wider tyre perform to it's maximum, any way i digress (waffle )
Glad the Deli and you are fine
_________________
No Deli anymore, Mk2 Pajero instead, 2" suspension and body lift, 35's, twin winches etc |
|
| Back to top |
|
|
|
FAQ
Search
Watched Topics
Memberlist
Usergroups
Register
Profile
Log in to check your personal messages
Log in
Calendar
Chatrooms
Club Shop
