I need new tyres. I currently have Continentals 265/60/18. What affect will it have if I change the profile to 70 or 75? Just more under body clearance?
TIA.
Adrian
Whenarewethere said
08:22 PM Apr 4, 2023
70 is 6.9% increase in diameter, 75 is 10.2%. But obviously you only get half of this in height increase.
Best to look at a forum > tyre topic, for your particular car for any issues.
watsea said
11:29 PM Apr 4, 2023
Larger wheels likely means an adverse affect to the braking of the van.
Radar said
07:05 AM Apr 5, 2023
FootlooseFizzers wrote:
Greetings all,
I need new tyres. I currently have Continentals 265/60/18. What affect will it have if I change the profile to 70 or 75? Just more under body clearance?
TIA.
Adrian
Probably illegal size for the car.
Effects your gearing, braking, fuel economy.
There is probably more reason not to go that way but the first one is the main one.
Possum3 said
08:13 AM Apr 5, 2023
Wheel/tyre size is governed by Vehicle Design Rules VDR's, which must (repeat MUST) be adhered to to remain legally compliant to operate on Australian Roads. To change tyre sizes outside of approved size to vehicle specifications is not only illegal but potentially dangerous.
Changing wheel/tyre size totally changes a vehicle's dynamics.
If an accident is caused by a vehicle with "illegal" modifications, serious penalties, including fines, demerits and in the event of injury potential gaol time.
If you really believe you can improve a vehicle by changing wheel/tyre sizes - go get a Licensed Automotive Engineer to modify your vehicle's specifications - People selling wheels/tyres are not Automotive Engineers and are not qualified to alter vehicle handling aspect.
Jaahn said
08:24 AM Apr 5, 2023
Surely the last couple of answers are not serious. Probably 50% of twincab utes and 4WDs have non standard tires and also wheels and tire changed. Wow does that mean that they are all liable to be unsafe and fall over or worse ??
Hmm make your own decision !! Not be influenced by a couple of old scare mongerers on a forum !! By their standard my car, small sedan, is flouting the law and liable to land me in hospital/jail/debters prison any day soon. However they have been on there for quite some years and pass our yearly rego inspection. Jaahn
-- Edited by Jaahn on Wednesday 5th of April 2023 08:29:56 AM
watsea said
10:03 AM Apr 5, 2023
Originally I thought this was about tyre size on a van. I should have realised it was about a vehicle. An increase in tyre profile without a wheel rim change will give more ground clearance and greater cushioning effect of the tyres. Maybe that is good for offroad work but what are you using the vehicle for roads or off-road? Race road cars have low profile tyres for better road holding etc. If the overall wheel diameter is larger, it will make the overall gearing of the vehicle "taller" and with "taller" gears, it is more difficult for the vehicle to get moving, especially towing a van or heavy trailer. "Taller" gears do not always mean better vehicle efficiency or fuel consumption, often reduced.
-- Edited by watsea on Wednesday 5th of April 2023 10:13:21 AM
FootlooseFizzers said
10:26 AM Apr 5, 2023
thanks everyone for your responses. I should have thought it through more before I posted. It was really out of idle curiosity but it has certainly raised some good points.
Adrian
Possum3 said
11:28 AM Apr 5, 2023
Jaahn wrote:
Surely the last couple of answers are not serious. Probably 50% of twincab utes and 4WDs have non standard tires and also wheels and tire changed. Wow does that mean that they are all liable to be unsafe and fall over or worse ?
Very serious! The Law doesn't recognise common practice when it comes to the Law; "The Law is Law because Law is Law"
Many people are in breach of many Laws and will in all probability never be penalised - but; when/if "SH1T hits the Fan" expect to be penalised up to the hilt.
yobarr said
12:42 PM Apr 5, 2023
FootlooseFizzers wrote:
thanks everyone for your responses. I should have thought it through more before I posted. It was really out of idle curiosity but it has certainly raised some good points. Adrian
Waste of time I reckon, as you'd gain only 1" more ground clearance. In some situations an inch can make a big difference, but on this occasion all you're doing is risking the car perhaps being illegal because of changed tyre size? Cheers
rgren2 said
12:44 PM Apr 5, 2023
watsea wrote:
Originally I thought this was about tyre size on a van. I should have realised it was about a vehicle. An increase in tyre profile without a wheel rim change will give more ground clearance and greater cushioning effect of the tyres. Maybe that is good for offroad work but what are you using the vehicle for roads or off-road? Race road cars have low profile tyres for better road holding etc. If the overall wheel diameter is larger, it will make the overall gearing of the vehicle "taller" and with "taller" gears, it is more difficult for the vehicle to get moving, especially towing a van or heavy trailer. "Taller" gears do not always mean better vehicle efficiency or fuel consumption, often reduced.
-- Edited by watsea on Wednesday 5th of April 2023 10:13:21 AM
Surely the last couple of answers are not serious. Probably 50% of twincab utes and 4WDs have non standard tires and also wheels and tire changed. Wow does that mean that they are all liable to be unsafe and fall over or worse ??
Hmm make your own decision !! Not be influenced by a couple of old scaremongerers on a forum !! By their standard my car, small sedan, is flouting the law and liable to land me in hospital/jail/debters prison any day soon. However they have been on there for quite some years and pass our yearly rego inspection. Jaahn
Hi Jaahn. Given your own age I must say that I'm surprised at your stance on this issue.
Surely you realise that as we age we generally become wiser and more erudite? Cheers
watsea said
12:59 PM Apr 5, 2023
rgren2 wrote:
I wouldnt really call these low profile.
I know the OP was not meaning real low profile tyres. I merely mentioned race cars as an example to try to get a message across.
Kebbin said
03:12 PM Apr 5, 2023
Depending on the State you are in the allowable tyre size is different. The '60' represents 60% of 265 = 159 this is the Aspect Size not the Profile as I and most others have called it.
I think your desired changes will be within the guidelines but to be sure contact your transport dept. or any tyre dealer as they would need to know the regulations.
Warren-Pat_01 said
01:00 PM Apr 9, 2023
Hi Adrian,
How accurate is your speedo with the current tyres fitted? Increasing the profile may hit your hip pocket in speeding fines.
My car was fitted with 255/70/17 HTs - I asked the dealer to fit the wheels off the next model down the range - 16" (245/70/16 AT). The speedo was out a bit so I drove with "Bert" telling me "You are over the speed limit" - then when the tyres were to be changed, I went to the more common 265/70/16 & the speedo is now spot on.
The car dealer wasn't very helpful saying "that providing you don't exceed (real) 100kph, the car is legal. The speedo can read down to 85kph & still the car is legal". I said try telling a B-double driver sitting behind you that's it's ok to be driving slower.
Greetings all,
I need new tyres. I currently have Continentals 265/60/18. What affect will it have if I change the profile to 70 or 75? Just more under body clearance?
TIA.
Adrian
70 is 6.9% increase in diameter, 75 is 10.2%. But obviously you only get half of this in height increase.
Best to look at a forum > tyre topic, for your particular car for any issues.
Probably illegal size for the car.
Effects your gearing, braking, fuel economy.
There is probably more reason not to go that way but the first one is the main one.
Changing wheel/tyre size totally changes a vehicle's dynamics.
If an accident is caused by a vehicle with "illegal" modifications, serious penalties, including fines, demerits and in the event of injury potential gaol time.
If you really believe you can improve a vehicle by changing wheel/tyre sizes - go get a Licensed Automotive Engineer to modify your vehicle's specifications - People selling wheels/tyres are not Automotive Engineers and are not qualified to alter vehicle handling aspect.
Surely the last couple of answers are not serious. Probably 50% of twincab utes and 4WDs have non standard tires and also wheels and tire changed. Wow does that mean that they are all liable to be unsafe and fall over or worse ??
Hmm make your own decision !! Not be influenced by a couple of old scare mongerers on a forum !! By their standard my car, small sedan, is flouting the law and liable to land me in hospital/jail/debters prison any day soon. However they have been on there for quite some years and pass our yearly rego inspection.
Jaahn
-- Edited by Jaahn on Wednesday 5th of April 2023 08:29:56 AM
Originally I thought this was about tyre size on a van. I should have realised it was about a vehicle.
An increase in tyre profile without a wheel rim change will give more ground clearance and greater cushioning effect of the tyres. Maybe that is good for offroad work but what are you using the vehicle for roads or off-road? Race road cars have low profile tyres for better road holding etc.
If the overall wheel diameter is larger, it will make the overall gearing of the vehicle "taller" and with "taller" gears, it is more difficult for the vehicle to get moving, especially towing a van or heavy trailer. "Taller" gears do not always mean better vehicle efficiency or fuel consumption, often reduced.
-- Edited by watsea on Wednesday 5th of April 2023 10:13:21 AM
Adrian
Very serious! The Law doesn't recognise common practice when it comes to the Law; "The Law is Law because Law is Law"
Many people are in breach of many Laws and will in all probability never be penalised - but; when/if "SH1T hits the Fan" expect to be penalised up to the hilt.
Waste of time I reckon, as you'd gain only 1" more ground clearance. In some situations an inch can make a big difference, but on this occasion all you're doing is risking the car perhaps being illegal because of changed tyre size? Cheers
Hi Jaahn. Given your own age I must say that I'm surprised at your stance on this issue.
Surely you realise that as we age we generally become wiser and more erudite? Cheers
I know the OP was not meaning real low profile tyres. I merely mentioned race cars as an example to try to get a message across.
I think your desired changes will be within the guidelines but to be sure contact your transport dept. or any tyre dealer as they would need to know the regulations.
How accurate is your speedo with the current tyres fitted? Increasing the profile may hit your hip pocket in speeding fines.
My car was fitted with 255/70/17 HTs - I asked the dealer to fit the wheels off the next model down the range - 16" (245/70/16 AT). The speedo was out a bit so I drove with "Bert" telling me "You are over the speed limit" - then when the tyres were to be changed, I went to the more common 265/70/16 & the speedo is now spot on.
The car dealer wasn't very helpful saying "that providing you don't exceed (real) 100kph, the car is legal. The speedo can read down to 85kph & still the car is legal". I said try telling a B-double driver sitting behind you that's it's ok to be driving slower.