T5 Tyres 17" what is available in OZ

[greymad]

I had Toyo HO2 and then HO8 tyres on my Hiace, and they were excellent, giving me around 60,000 km on a set.

The thing about replacement tyres is the load rating and speed rating. It is one thing to get the correct size, but if the load rating and/or speed rating is not correct, this is where you have issues with insurers.

I appreciate the point you make, but why does a 132kw T5 have to have W rated tyres which are good, apparently, for 247km/hr (!)
And for that matter, the same tyres (103's) have a load capability of 875kg each - ie a T5 with an all up weight of 3,500kg (!)
Might there be a bit of over conservative cover-our-backsides just-in-case-someone-sues procedure going on here?

[wai]

I appreciate the point you make, but why does a 132kw T5 have to have W rated tyres which are good, apparently, for 247km/hr (!)
And for that matter, the same tyres (103's) have a load capability of 875kg each - ie a T5 with an all up weight of 3,500kg (!)
Might there be a bit of over conservative cover-our-backsides just-in-case-someone-sues procedure going on here?

Don't worry, there are other weird things.

Take my Caddy. If you have 16" wheels the tyres are 205/55 R16 94T, but if you have 17" wheels, then the tyres are 205/50R17 93T.

These are for the same vehicle, so why when you go up in rim diameter can the tyre have a lower load carrying rating? Surely both should be 94T or 93T for both wheel diameters.

Also, the placard shows images for 2 people and one bag of luggage, and 5 people and 3 bags of luggage. The vehicle is a 7 seater! Does this mean you cannot carry more than 5 people in a 7 seater (a little tongue in cheek)?

Makes you wonder.

[Diesel_vert]

why does a 132kw T5 have to have W rated tyres which are good, apparently, for 247km/hr (!)

EU regulations require vehicle manufacturers to specify a tyre with a speed index which is not less that the the vehicle's top speed multiplied by a factor of 1.05

Manufacturers may also specify tyres in excess of a vehicle's top speed for reasons of performance (of which there are many types of criteria), because a tyre's speed index may also be used as a rough indicator of a tyre's construction and characteristics.

The thing about replacement tyres is the load rating and speed rating. It is one thing to get the correct size, but if the load rating and/or speed rating is not correct, this is where you have issues with insurers.

In any case, most Australian states permit you to fit a tyre with a speed index less than the vehicle's top speed - provided that the vehicle's top speed is 180 km/h or over (exact wording varies from juristiction).

Though I wouldn't mess about with the load index.

And for that matter, the same tyres (103's) have a load capability of 875kg each - ie a T5 with an all up weight of 3,500kg (!)

As well as all the tyres being able to support the gross vehicle mass, the tyres on each axle must also be able to support the gross axle weight.

Might there be a bit of over conservative cover-our-backsides just-in-case-someone-sues procedure going on here?

One should also be aware that, for a standard load tyre, maximum load capacity is achieved at 2.5 bar (36 psi). For an extra load tyre, maximum load capacity is achieved at 2.9 bar (42 psi). These figures have nothing to do with the maximum inflation pressure a tyre is able to support, which is indicated on the sidewall.

It can be easy to overload tyres through underinflation - even if a tyre is capable of supporting higher loads at the appropriate inflation pressures.

Hence, it is appropriate to have safety margins.

Don't worry, there are other weird things.

Take my Caddy. If you have 16" wheels the tyres are 205/55 R16 94T, but if you have 17" wheels, then the tyres are 205/50R17 93T.

These are for the same vehicle, so why when you go up in rim diameter can the tyre have a lower load carrying rating? Surely both should be 94T or 93T for both wheel diameters.

The load index of a passenger tyre is pre-designated by its size, and can be classified as either "standard load" or "extra load". For example;

"205/55 R16 91T" is standard load. "205/55 R16 94T XL" is extra load.

"205/50 R17 89T" is standard load. "205/50 R17 93T XL" is extra load.

Thus, there are no such fitments as "205/55 R16 93T" or "205/50 R17 94T", etc.

Also, the placard shows images for 2 people and one bag of luggage, and 5 people and 3 bags of luggage. The vehicle is a 7 seater! Does this mean you cannot carry more than 5 people in a 7 seater (a little tongue in cheek)?

If it's anything typical of a European car, the diagram should not be strictly interpreted as literal. Rather, it is simply meant to represent "half load" and "full load". Such pictograms, cryptic they may be to people of English-speaking backgrounds (who aren't accustomed to this sort of thing), are common in Europe due to the sheer number of languages spoken on the continent.

[greymad]

EU regulations require vehicle manufacturers to specify a tyre with a speed index which is not less that the the vehicle's top speed multiplied by a factor of 1.05

Manufacturers may also specify tyres in excess of a vehicle's top speed for reasons of performance (of which there are many types of criteria), because a tyre's speed index may also be used as a rough indicator of a tyre's construction and characteristics.



In any case, most Australian states permit you to fit a tyre with a speed index less than the vehicle's top speed - provided that the vehicle's top speed is 180 km/h or over (exact wording varies from juristiction).

Though I wouldn't mess about with the load index.



As well as all the tyres being able to support the gross vehicle mass, the tyres on each axle must also be able to support the gross axle weight.



One should also be aware that, for a standard load tyre, maximum load capacity is achieved at 2.5 bar (36 psi). For an extra load tyre, maximum load capacity is achieved at 2.9 bar (42 psi). These figures have nothing to do with the maximum inflation pressure a tyre is able to support, which is indicated on the sidewall.

It can be easy to overload tyres through underinflation - even if a tyre is capable of supporting higher loads at the appropriate inflation pressures.

Hence, it is appropriate to have safety margins.



The load index of a passenger tyre is pre-designated by its size, and can be classified as either "standard load" or "extra load". For example;

"205/55 R16 91T" is standard load. "205/55 R16 94T XL" is extra load.

"205/50 R17 89T" is standard load. "205/50 R17 93T XL" is extra load.

Thus, there are no such fitments as "205/55 R16 93T" or "205/50 R17 94T", etc.



If it's anything typical of a European car, the diagram should not be strictly interpreted as literal. Rather, it is simply meant to represent "half load" and "full load". Such pictograms, cryptic they may be to people of English-speaking backgrounds (who aren't accustomed to this sort of thing), are common in Europe due to the sheer number of languages spoken on the continent.

Wow! that's comprehensive ... I'm impressed - and invite your comment(s) on the following.
I put the campervan on the local weighbridge and with full tanks - both fuel as well as water, and with driver & passenger on board it scaled 2650kg.
I see that Bridgestone make ER300 215/60 R17 (96H) which have an OD of 690 ... within 5mm of the current 235/55 R17 (103W)
While a profile change from 55 to 60 doesn't seem much, my hope is that it might improve the crash bang bump thump "quality" of the outfit which at the moment is almost intolerable on corrugated roads.
Over to you.

[Col Collyer]

I let my tyres down to 35lb from around 50. Now they have a flat on the bottom, and the ride is way better. Time will tell how it affects wear.

[Diesel_vert]

Wow! that's comprehensive ... I'm impressed - and invite your comment(s) on the following.
I put the campervan on the local weighbridge and with full tanks - both fuel as well as water, and with driver & passenger on board it scaled 2650kg.
I see that Bridgestone make ER300 215/60 R17 (96H) which have an OD of 690 ... within 5mm of the current 235/55 R17 (103W)
While a profile change from 55 to 60 doesn't seem much, my hope is that it might improve the crash bang bump thump "quality" of the outfit which at the moment is almost intolerable on corrugated roads.
Over to you.

I've noted your comments re: weighbridge, but fitting a tyre with a lower load index that hasn't been approved by the manufacturer means the vehicle can be rendered unroadworthy - which has consequences for the registered owner and whoever's driving it (liability, insurance, etc).

In any case, I predict that 215/60 R17 wouldn't be noticeably more comfortable than 235/55 R17, because you lose too much width (235 to 215) compared to the gain in height (55 to 60).

It would be better to replace your current summer tyres for an all-season tyre like the Kumho Ecsta LX Platinum (KU27). Or increase the width from 235/55 R17 to 245/55 R17 with the side effect of making the speedometer less underestimate the vehicle's speed.

...

Now, I'm not here to tell you what you can and can't do, so if you still want to go ahead, I strongly recommend the tyres are at least able to support the maximum axle weight and the maximum vehicle weight, otherwise there is a serious safety risk.

The standard load version "215/60 R17 96H" has a max. load capacity of 710 kg, so it can support 1420 kg per axle and 2840 kg in total.

The extra load version "215/60 R17 100H XL" has a max. load capacity of 800 kg, so it can support 1600 kg per axle and 3200 kg in total - but this size appears to be exceedingly rare on the market.

So, what are the maximum axle weights (front & rear) and the maximum vehicle weight? The figures should be found on a sticker or a plate on the vehicle itself, maybe somewhere on the pillars.

[brad]

People seem to forget that a vehicle is not on static display & that the load is not distributed evenly & the big hits (potholes, etc) are often concentrated on a single tyre.

I think a lot of the issues with hard / crashy ride might be the OEM damper valving. Someone mentioned earlier (another thread) that they fitted Koni & never looked back. I think reducing tyre pressure to compensate for poorly valved dampers is like walking on your hands because you have a broken leg that you can't be bothered getting fixed.

[Diesel_vert]

People seem to forget that a vehicle is not on static display & that the load is not distributed evenly & the big hits (potholes, etc) are often concentrated on a single tyre.

That is just one of many reasons why car makers might specify tyres with a load index in excess of the maximum axle and vehicle weights.

A tyre's maximum load capacity is only an indicator of one characteristic - it's ability to safely support that weight. Nothing more.

It gives no indication of how other characteristics come into play on a particular vehicle, such as stability, handling, wear, comfort, grip, aquaplaning, noise and god knows how many other parameters a car maker takes into account when choosing a tyre.

[Col Collyer]

People seem to forget that a vehicle is not on static display & that the load is not distributed evenly & the big hits (potholes, etc) are often concentrated on a single tyre.

I think a lot of the issues with hard / crashy ride might be the OEM damper valving. Someone mentioned earlier (another thread) that they fitted Koni & never looked back. I think reducing tyre pressure to compensate for poorly valved dampers is like walking on your hands because you have a broken leg that you can't be bothered getting fixed.

Brad... I have a slightly different view about tyre pressures. Transporters ride quality varies with weight, and at heavier weights requires higher tyre pressures. I guess the reverse is true, and as mine spends most its life nearly empty, I recon the lower pressures are warrented. It certainly improves the ride, and they don't look or handle "flat"
Col