Tyre pressures for 18" wheels
- Thread starter Captain Mainwaring
- Start date
TheDumbOx
Member
Yep, it's saying max pressure 44psi. Would a car have a load rating of 875kg though? We bought it from the local independent VW specialist (it was his personal van) so kind of assumed it would be pukka. Photos for reference:Hi.. So to understand is it printed/embossed on the tyre wall max pressure 44psi. ( on my Michelin tyres it states 50psi ) Photo would confirm…so id contact tyre dealer as you may be on car derived tyres and not van Xl tyres
Umm…its not a premium brand that you would normally be expected to be constructed to withstand higher pressures hence why some Michelin and Goodyear go to Max 50psi……unfortunately not all tyres are equal…The issue is 44psi would be a cold inflation figure so you should operate at a lower figure to allow for temperature variation..ie heat/pressure expansion…in short to be safe you need to fit tyres that allow you to carry the weights for your intend purpose with a higher maximum PSI….unfortunately costs come before quality…Don’t get me wrong the tyres are safe if you only used it as a runaround and don’t carry any weight..it’s never easy to stomach that some one has fitted tyres that aren’t suitable for a commercial vehicle…many SUV’s have similar tyres
If a tyre is rated 103 (875kg) and its max pressure is 45psi then it will support that max weight at it max pressure and its therefore likely to have a stronger construction to another tyre rated 103 at 50psi as it requires less air pressure to support the same weight. Ideally you would need to find the axle weights in service and convert this to a percentage of the max load rating of the tyres on that axle (1750kg in this case) then use this % when setting pressure with 45psi being 100%.
Example - if axle weight is 1400kg this is 80% of max for that axle based on tyre load rating. So set tyre pressure to 80% of 45psi = 36 psi.
Example - if axle weight is 1400kg this is 80% of max for that axle based on tyre load rating. So set tyre pressure to 80% of 45psi = 36 psi.
As a guide VW supply tyre inflation stickers and recommend pressures For weight carried…. Assuming the tyre is able to withstand the highest pressure for a fully laden vehicle your deemed safe.. However if in this case the tyre has a max of 44psi your never going to comply with VW’s recommendations for a fully laden load …so in the case of this Michelin tyre…..
Your in compliance…..Your need to consult a tyre dealer to fully understand why a tyre that’s got a lower max pressure limit is fitted regardless of load rating and possibly your insurance company may want to know if investigating a accident why your not using a compliant tyre…this is probably a warning that not all tyres are equal…
Your in compliance…..Your need to consult a tyre dealer to fully understand why a tyre that’s got a lower max pressure limit is fitted regardless of load rating and possibly your insurance company may want to know if investigating a accident why your not using a compliant tyre…this is probably a warning that not all tyres are equal…
See my post above, the sticker is a guide based on OEM tyres, tyres from other manufacturers will differ in their construction and therefore are designed for different pressures at a specific load.
103 or 875kg means just that otherwise why would they bother to apply the rating?
The average driver would struggle to workout a working pressure based on a tyre 44psi/875kg as the guide sticker does not cover this… ..also that Michelin cross climate tyre is not a OEM tyre …When ever buying tyres you’re supposed to fit equal too or better than the original fitment ..Yes the load rating is important but in this case it’s the pressure rating that’s thrown a curveball .
Safety is paramount…..but if the tyre does not fit the expected working pressure range its the wrong tyre….Cheers
Safety is paramount…..but if the tyre does not fit the expected working pressure range its the wrong tyre….Cheers
TheDumbOx
Member
Thanks everyone for attempting to unmuddy the waters a bit. I have compromised and put the front tyres on at 40psi, so slightly lower than the recommended weight and below the max pressure for the tyre. Together we probably weigh about the same as 1.5 average men, so I'm hoping being slightly under will do us for now. The back is fairly empty (we only have sound deadening and ply all round) so it will hopefully be ok on 36psi. I'll put it up to 40psi when we eventually get a wooden slatted bed plus our camping gear.
Mr TDO agrees we can't transport the bike until we get new tyres (I don't actually want it in there anyway, so bonus!) and when we change them we've agreed we'll get good quality ones which are more rugged. The one thing I'm really cheesed off with (and I know, caveat emptor) is the guy who owned it previously, runs a VW garage and this was his own van. I get someone who doesn't know better doing this, but someone who does? Just why? smdh.
Mr TDO agrees we can't transport the bike until we get new tyres (I don't actually want it in there anyway, so bonus!) and when we change them we've agreed we'll get good quality ones which are more rugged. The one thing I'm really cheesed off with (and I know, caveat emptor) is the guy who owned it previously, runs a VW garage and this was his own van. I get someone who doesn't know better doing this, but someone who does? Just why? smdh.
TheDumbOx
Member
Hi Gavinda,
I hear you, and I'm very much reassured from what you have said that they are ok.
However, the recommended front pressure is 44psi, so absolutely at the max of the pressure rating, and the back, if fully loaded, is 48psi. This is 4psi over the max pressure rating of the tyres. So yes, it is fine for now, since we don't have anything to put in the back yet, but it won't be fine in the future. I would personally feel more comfortable driving if I know the tyres can take more pressure and more load.
Hi everyone! newly minted T6.1 owners with a new T32 Kombi for family adventures. We're lifelong car owners so we're excited at the adventures ahead.
The van's last owner installed some aftermarket wheels and tyres which are larger than the standard and the tyres are rated to 255/45ZR18 103W
Taken a look at the sticker in the door which says standard tyres are 215/60/R17C followed by 109/107T
I've taken a look around and cant find anything definitive that can give me figures for the tyre pressures I should. I'm planning on visiting the local tyre fitter I've used in the past, but wanted to ask the community 1st.
Thanks
The van's last owner installed some aftermarket wheels and tyres which are larger than the standard and the tyres are rated to 255/45ZR18 103W
Taken a look at the sticker in the door which says standard tyres are 215/60/R17C followed by 109/107T
I've taken a look around and cant find anything definitive that can give me figures for the tyre pressures I should. I'm planning on visiting the local tyre fitter I've used in the past, but wanted to ask the community 1st.
Thanks
@BognorMotors will know, when I bought my T6.1 recently with 20 inch alloy wheels the pressures were set at 50psi front and 55psi rear and Bognor motors told me 38-40 psi which I’m now running my van on.
John.
John.
36-40psi for a 20” 265/40 or 275/35.
I’ll get you the correct 18” tyre pressures when I get into the office this morning
The 215/60R17C OEM tyres are most likely D-load / 8 Plyrated tyres
Loadindex 109 /maxload 1030kg AT 65psi, for upto 160kmph/99mph.
The 255/40ZR18 103 is most likely an XL / reinforced/ extraload tyre .
103/ maxload 875kg AT 42psi. Also for upto 99mph .
Then first we have to determine if they are allowed.
For that you have to seach for them maximum permissable axle weight of the car.
OEM would cover MPAW of 2060kg.
18" would cover 1750kg MPAW.
If enaugh then this " pigheaded Dutch selfdeclared tyrepressure-specialist " can calculate the pressures for you.
If your maximum used speed is below 99mph ( and wont go over for even a minute) it will give not higher then 42psi.
Lineair calc is not even that bad, but I use a better one then official used, I got hold of and went running with end 2007.
But first add 10% to the axleload for reserve, fuelsaving, ridingquality, befire calculating.
But check the MPAW's, and if XL// or not.
Because I only react on tyrepressure related questions, I wont introduce myself in a seperate topic. Registered to give this info , dont have a T6 ( VW ??)
Loadindex 109 /maxload 1030kg AT 65psi, for upto 160kmph/99mph.
The 255/40ZR18 103 is most likely an XL / reinforced/ extraload tyre .
103/ maxload 875kg AT 42psi. Also for upto 99mph .
Then first we have to determine if they are allowed.
For that you have to seach for them maximum permissable axle weight of the car.
OEM would cover MPAW of 2060kg.
18" would cover 1750kg MPAW.
If enaugh then this " pigheaded Dutch selfdeclared tyrepressure-specialist " can calculate the pressures for you.
If your maximum used speed is below 99mph ( and wont go over for even a minute) it will give not higher then 42psi.
Lineair calc is not even that bad, but I use a better one then official used, I got hold of and went running with end 2007.
But first add 10% to the axleload for reserve, fuelsaving, ridingquality, befire calculating.
But check the MPAW's, and if XL// or not.
Because I only react on tyrepressure related questions, I wont introduce myself in a seperate topic. Registered to give this info , dont have a T6 ( VW ??)
Just take into account that the recomended pressures are what the vehicle would have been tested with for emissions, so doesn't take into account comfort or wear. It's likely that you'll want them a smidge lower.
A lot is trial at error, as few vans weigh the same and have an equally distributed load all of the time.
A lot is trial at error, as few vans weigh the same and have an equally distributed load all of the time.
I’ve merged your thread in to one of several existing threads on tyre pressures for 255/45/18 - they’re an OEM size but not as common as 16” and 17”, which is probably why the pressures aren’t shown on your door sticker.
Here’s the definitive answer:
Hope this helps
Tyre pressures for 18" wheels
Hi guys, my first proper post apart from the new members forum so please go easy. I have looked through other posts and also trawled through the T5 forum but cannot find a definitive answer so hopefully I am not duplicating I took delivery of my T32 Kombi 4-Motion a few weeks ago but replaced...
Thanks for the replies. Much appreciated. Still learning the ropes on the forum so thanks also for merging my post.I’ve merged your thread in to one of several existing threads on tyre pressures for 255/45/18 - they’re an OEM size but not as common as 16” and 17”, which is probably why the pressures aren’t shown on your door sticker.
Here’s the definitive answer:
Hope this helps
Tyre pressures for 18" wheels
Hi guys, my first proper post apart from the new members forum so please go easy. I have looked through other posts and also trawled through the T5 forum but cannot find a definitive answer so hopefully I am not duplicating I took delivery of my T32 Kombi 4-Motion a few weeks ago but replaced...www.t6forum.com
VWOnTheRoad
New Member
Hi, I’ve just come here looking for the same answer for my T6 T32 SWB with 235/55 R18 104H Tyres. How have you been getting on with the recommendations,what are you using now? Thanks.
