Hi folks.
I was asked a question today which I don’t know the answer.
Why is the tread depth of an LGV tyre 1mm when a vehicle up to 3.5 tonne is 1.6 mm.
To be honest I haven’t a clue. I have tried to find the information but can’t .
Any help would be great tah
I should of added minimum tread depth for each category.
chippy:
Hi folks.I was asked a question today which I don’t know the answer.
Why is the tread depth of an LGV tyre 1mm when a vehicle up to 3.5 tonne is 1.6 mm.
To be honest I haven’t a clue. I have tried to find the information but can’t .Any help would be great tah
Had a look on one web site and thats the legal minimum,
tyres-online.co.uk/techinfo/tread_depth.asp
or
staysure-tyres.co.uk/tyrelaws.htm
I would of thought truck would be higher minimum than a car…
tread is on a tyre for wet roads. I am asuming lorrys are heavier so they have less chance of aquaplaning so they can have a lower tread depth. light vehicles are more likely to aquaplane so have to have a minimum higher tread depth
bubsy06:
tread is on a tyre for wet roads. I am asuming lorrys are heavier so they have less chance of aquaplaning so they can have a lower tread depth. light vehicles are more likely to aquaplane so have to have a minimum higher tread depth
That may be it Busby06 but is there a clear legal reason of why the tread depth is different? This is what I can’t find out " The why bit"
Thanks Pecjam23 for the links, I have looked at them before and others but still can’t find a reason
chippy:
Hi folks.I was asked a question today which I don’t know the answer.
Why is the tread depth of an LGV tyre 1mm when a vehicle up to 3.5 tonne is 1.6 mm.
To be honest I haven’t a clue. I have tried to find the information but can’t .Any help would be great tah
you are correct dont ask me why though i use to be a m.o.t tester and i just had to follow the rules laid down by the minister no quetions asked. if it was in the book as a fail it failed if it weren’t in there it passed 
Here is the answer.
Blame Europe 
http://www.tyres-online.co.uk/techinfo/tread_depth.asp
And here is the test result from MIRA
http://www.rospa.com/roadsafety/advice/motorvehicles/tread_depth.htm
bubsy06:
tread is on a tyre for wet roads. I am asuming lorrys are heavier so they have less chance of aquaplaning so they can have a lower tread depth. light vehicles are more likely to aquaplane so have to have a minimum higher tread depth
That argument may work but in that case why is the limit for 186mph motorcycles still only 1 millimetre?- 
Wheel Nut:
Here is the answer.Blame Europe
http://www.tyres-online.co.uk/techinfo/tread_depth.asp
And here is the test result from MIRA
http://www.rospa.com/roadsafety/advice/motorvehicles/tread_depth.htm
Hi Wheelnut . i can’t find the answer to my question on these links as to why
the minimum tread depth for a vehicle over 3.5 tonne is different to one that is under 3.5 tonne? Am I missing something?
chippy:
Hi folks.I was asked a question today which I don’t know the answer.
Why is the tread depth of an LGV tyre 1mm when a vehicle up to 3.5 tonne is 1.6 mm.
To be honest I haven’t a clue. I have tried to find the information but can’t .Any help would be great tah
OH DEARY ME 
- that is one of the LGV on-test safety questions and the one that seems to get asked the most on test. 
- Tell me how you would check your tyres to ensure that they are correctly inflated, have sufficient tread depth and that there general condition is safe to use on the road?
Follow manufacturer’s guide, using appropriate equipment, check and adjust pressures when tyres are cold. Must have a tread depth of at least 1mm (1.6 for cars) across ¾ of the breadth of the tread and in a continuous band around the entire circumference. There should be no cuts, damage or signs of cord visible at the sidewalls.
ROG:
chippy:
Hi folks.I was asked a question today which I don’t know the answer.
Why is the tread depth of an LGV tyre 1mm when a vehicle up to 3.5 tonne is 1.6 mm.
To be honest I haven’t a clue. I have tried to find the information but can’t .Any help would be great tah
OH DEARY ME
- Tell me how you would check your tyres to ensure that they are correctly inflated, have sufficient tread depth and that there general condition is safe to use on the road?
Follow manufacturer’s guide, using appropriate equipment, check and adjust pressures when tyres are cold. Must have a tread depth of at least 1mm (1.6 for cars) across ¾ of the breadth of the tread and in a continuous band around the entire circumference. There should be no cuts, damage or signs of cord visible at the sidewalls.
No I think he wants to know why lorrys have a minimum of 1mm and cars have 1.6mm why arnt they both 1.6mm
Because you can make money betting on car drivers never checking tread depth until they get a flat?
Truck tyres currently have a 1mm legal minimum tread depth - which many are trying to drive up to 1.6mm - for exactly the same reasons as they want to see 3mm for car tyres.
bubsy06:
ROG:
chippy:
Hi folks.I was asked a question today which I don’t know the answer.
Why is the tread depth of an LGV tyre 1mm when a vehicle up to 3.5 tonne is 1.6 mm.
To be honest I haven’t a clue. I have tried to find the information but can’t .Any help would be great tah
OH DEARY ME
- Tell me how you would check your tyres to ensure that they are correctly inflated, have sufficient tread depth and that there general condition is safe to use on the road?
Follow manufacturer’s guide, using appropriate equipment, check and adjust pressures when tyres are cold. Must have a tread depth of at least 1mm (1.6 for cars) across ¾ of the breadth of the tread and in a continuous band around the entire circumference. There should be no cuts, damage or signs of cord visible at the sidewalls.No I think he wants to know why lorrys have a minimum of 1mm and cars have 1.6mm why arnt they both 1.6mm
OOOPS 
- SORRY chippy - got wrong end of stick - or rubber.
ROG:
bubsy06:
ROG:
chippy:
Hi folks.I was asked a question today which I don’t know the answer.
Why is the tread depth of an LGV tyre 1mm when a vehicle up to 3.5 tonne is 1.6 mm.
To be honest I haven’t a clue. I have tried to find the information but can’t .Any help would be great tah
OH DEARY ME
- Tell me how you would check your tyres to ensure that they are correctly inflated, have sufficient tread depth and that there general condition is safe to use on the road?
Follow manufacturer’s guide, using appropriate equipment, check and adjust pressures when tyres are cold. Must have a tread depth of at least 1mm (1.6 for cars) across ¾ of the breadth of the tread and in a continuous band around the entire circumference. There should be no cuts, damage or signs of cord visible at the sidewalls.No I think he wants to know why lorrys have a minimum of 1mm and cars have 1.6mm why arnt they both 1.6mm
OOOPS
Thats quite ok Rog. I was asked by a senior manager at a city council as part of a assessment, in which I was doing a presentation on tyre checks.
I didn’t know the answer and having researched it on here and elsewhere before the visit I am still none the wiser. I just admitted to him I didn’t know. He didn’t tell me the answer either. Perhaps he doesn’t know, but there must be a reason for the difference
To be honest I didn’t think he would ask me why, there was a difference 
I must admit that it is one of the things that has always had me wondering why the much larger vehicle should be allowed the lowest tread depth
I guess its all to do with physics - the heavier the tyre on the road the more water it can displace, and also the greater surface area of rubber.
What I find strange is that a 3.5 tonne van needs 1.6mm of tread yet if you convert it to a minibus - same floor pan, but carrying passengers, it only needs 1mm! - unless rules have changed unbeknown to me.
ROG:
I must admit that it is one of the things that has always had me wondering why the much larger vehicle should be allowed the lowest tread depth
It had me wondering too, only now I am on the hunt to find out. I can then phone the senior and tell him, even if I have blown the the Q&A session and the contract. I got all the other related stuff right, but he caught me out on that one.
I did try and find out but there doesn’t seem to be an answer so far 
The only answer I can find is that cars minimum tread used to be 1mm but got changed to 1.6mm but they did not change motorbikes and lorrys up to 1.6mm.
chippy:
ROG:
I must admit that it is one of the things that has always had me wondering why the much larger vehicle should be allowed the lowest tread depthIt had me wondering too, only now I am on the hunt to find out. I can then phone the senior and tell him, even if I have blown the the Q&A session and the contract. I got all the other related stuff right, but he caught me out on that one.
I did try and find out but there doesn’t seem to be an answer so far
Chippy, i’d very much doubt if he was upset. I’d rather think he was impressed that you willingly admitted not knowing. A clear instant where bs would never work.
He’ll be even more impressed when you give him the right answer!