New Tyres and the New Ratings

[Mellow Matt]

I need a couple of rear tyres for my mx-5 soon, and was just going to buy a couple of Toyo T1Rs - that's what I've got on the front, I've found them pretty good and they've always been recommended in the past.

However, I've just seen that they've got pretty poor ratings on this new tyre rating system - on a scale of A-G, they get a G for fuel efficiency and an E for wet grip. The best rated tyre for my size (195/50/15) seems to be the Hanook Ventus Prime 2 K115 (never heard of them though?), with a efficiency rating of C and wet grip rating of B.

Should I just ignore this, and buy the T1Rs anyway, or should I heed the labels and go for another tyre?

The ratings don't mention dry grip (surely one of the most important factors?!), and I would've thought that more fuel efficient tyres generally meant less grippy, so it's all a bit unclear IMO...!

[Frances The Mute]

The tyre labelling system is essentially organised for the benfit of mongs.

They cover three different criterion - none of which actually answer any question that a keen driver would have regarding their performance.
Added to which, the thresholds between gradings can be very small, so a good tyre can have a poor rating. Oh yeah, they are mostly self certified at the moment as there is no stringent moderation of each entry which is unsurprising given the amount of tyres on the market. Confused? Thank Brussels.

Anyway, the T-1R is a decent tyre. Some complain it's a little too soft but ultimately, driving style, maintenance and vehicle type are the biggest influences on how a tyre will wear.

Given your car, I'd replace with a full set, too. Mixed axle pairs will often give poor balance qualities with this car.

[Disco You]

For a tyre to have a good rating for fuel efficiency it must have a low rolling resistance... I.e. low levels of grip...

[BFG TERRANO]

Ignore it, its a nonsense. My cousin is branch manager and my best mate his assistant in a tyre retailer. They tell me the figures between each letter of the rating are tiny. In much the same way as an EPC certificate for your house. Another box ticking mission for government. The additional fuel used between tyre brands is so small it can easily be outweighed by many other factors.

[Mellow Matt]

Excellent - these were the answers I was hoping for!

Ta

[RammyMP]

I was ordering some new tyres for her in doors and they were all rated G and G, I just ordered Pirellis!

[Mossyboy1978]

BFG TERRANO said:

Ignore it, its a nonsense. My cousin is branch manager and my best mate his assistant in a tyre retailer. They tell me the figures between each letter of the rating are tiny. In much the same way as an EPC certificate for your house. Another box ticking mission for government. The additional fuel used between tyre brands is so small it can easily be outweighed by many other factors.

Sorry but this is massively incorrect. The difference in fuel performance is considerable and savings can be in the hundred of pounds per year. Have a look at this - app.green-tyres.org.uk - a free app that tells you exactly how much you save depending on the tyre category you select. It's not small beer. The results are drawn from about 14months of independent scientific research at Munich University so they are correct. I know this for a fact because I worked with the scientists involved.

Anyone who thinks budget tyres like this offer minimal difference on fuel economy compared to premium tyres has it utterly wrong. Scientific fact proves the point.

[Mossyboy1978]

Disco You said:

For a tyre to have a good rating for fuel efficiency it must have a low rolling resistance... I.e. low levels of grip...

Let me also clarify on this point - low grip does not need to mean low fuel economy. Certain premium tyres about to come to market (often referred to as Green Tyres) combine both using very clever ploymers and rubbers that can change their structure depending on whether the car accelerates or brakes. The labelling has forced manufacturers to spend in this area and the result is tyres that don't trade one off from the other. You do not need to compromise but you are likely to have to spend more to get both fuel efficiency and grip in the wet.

[300bhp/ton]

Mossyboy1978 said:

Sorry but this is massively incorrect. The difference in fuel performance is considerable and savings can be in the hundred of pounds per year. Have a look at this - app.green-tyres.org.uk - a free app that tells you exactly how much you save depending on the tyre category you select. It's not small beer. The results are drawn from about 14months of independent scientific research at Munich University so they are correct. I know this for a fact because I worked with the scientists involved.

Anyone who thinks budget tyres like this offer minimal difference on fuel economy compared to premium tyres has it utterly wrong. Scientific fact proves the point.

ok followed that link, what a completely confusing website that just looks like it's there to fool the unwitty. Some rather basic issues like asking how many miles you do then wanting you to enter in how many litres per 100 km you use?? WTF written and designed by idiots or people who haven't really thought about the end user.

I can see no science at all on it, its just using some hidden figures in the back ground to generalise what you could save under ideal conditions. And lets not forget the bands are just that, so picking a tyre that's the lowest figure for a higher band will actually offer almost nothing over a tyre at the top of the band below it.


Science I like, but that site is just smoke & mirrors with a heavy dose of BS.


EDIT: found some additional controls for mpg. Still not a hugely helpful site though.

[RenesisEvo]

Mossyboy1978 said:

The difference in fuel performance is considerable and savings can be in the hundred of pounds per year.

Assuming the same car, I would wager that driving style has a far, far greater impact on mpg than tyre rolling resistance. Also, above 40-50mph, rolling resistance becomes secondary to aerodynamic drag in terms of what the engine has to overcome to maintain forward motion.

Was the data normalised for contact patch area? (eliminating variables such as axle load, tyre size, etc?)

[Mossyboy1978]

300bhp/ton said:

ok followed that link, what a completely confusing website that just looks like it's there to fool the unwitty. Some rather basic issues like asking how many miles you do then wanting you to enter in how many litres per 100 km you use?? WTF written and designed by idiots or people who haven't really thought about the end user.

I can see no science at all on it, its just using some hidden figures in the back ground to generalise what you could save under ideal conditions. And lets not forget the bands are just that, so picking a tyre that's the lowest figure for a higher band will actually offer almost nothing over a tyre at the top of the band below it.


Science I like, but that site is just smoke & mirrors with a heavy dose of BS.


EDIT: found some additional controls for mpg. Still not a hugely helpful site though.

Entitled to your opinion but I can send you the resarch documents that back up the calculations if you like. It's all completely independent and peer reviewed so your argument about smoke and mirrors falls down somehwat.

I agree that the website is designed for the European market whilst the app for smartphone/tablet is Uk specific so the latter will be easier to use and clearer for you. However, if you check the top right of the web version there is an option to switch to UK measurements which might make it easier. It is absolutely worth a download of the app though (free) just to try the better experience of the device-based version.

And I'm intruiged at what science you expected to see. Given your comments are all about the site being too complex did you really want to see the three page formulae that powers the whole thing?

[Mossyboy1978]

RenesisEvo said:

Assuming the same car, I would wager that driving style has a far, far greater impact on mpg than tyre rolling resistance. Also, above 40-50mph, rolling resistance becomes secondary to aerodynamic drag in terms of what the engine has to overcome to maintain forward motion.

Was the data normalised for contact patch area? (eliminating variables such as axle load, tyre size, etc?)

Actually - research shows that tyres account for between 25 and 30% of fuel consumption - most of which is just break rolling resistance.

Good point about speeds above 40mph but the resistance is still there and must still be overcome. Note also that the UK average speed acording to the AA is just above 30mph so most of the nation is dirving below this speed for most of their dricing time,

You are also right about driving style. In the app I sent a link to, if you change this variable it has a profound affect but it doesn't diminish the tyre's impact, just adds to it if you are a more cautious driver.

Not sure about contact patch area. I'll check that our.

[300bhp/ton]

Mossyboy1978 said:

Entitled to your opinion but I can send you the resarch documents that back up the calculations if you like. It's all completely independent and peer reviewed so your argument about smoke and mirrors falls down somehwat.

I agree that the website is designed for the European market whilst the app for smartphone/tablet is Uk specific so the latter will be easier to use and clearer for you. However, if you check the top right of the web version there is an option to switch to UK measurements which might make it easier. It is absolutely worth a download of the app though (free) just to try the better experience of the device-based version.

And I'm intruiged at what science you expected to see. Given your comments are all about the site being too complex did you really want to see the three page formulae that powers the whole thing?

Maybe I was being a bit hard tbh.

In terms of science, well a little expansion on the different categories would have been nice and if you are claiming 30% differences in mpg something to actually back this up rather than just some meaningless numbers that change due to an on screen slider.

[Matt UK]

OP, I used Toyo T1-Rs on my Mk1 MX5. Used them for road and track days.

Found them to be soft enough to provide decent grip, progressive at the edge which got the chassis up onto tiptoes and cheap enough to slap a new set on when the rears had been abused.

Ignore the tyre ratings.

[omgus]

Matt UK said:

OP, I used Toyo T1-Rs on my Mk1 MX5. Used them for road and track days.

Found them to be soft enough to provide decent grip, progressive at the edge which got the chassis up onto tiptoes and cheap enough to slap a new set on when the rears had been abused.

Ignore the tyre ratings.

I used them on my Scooby and MR2 Rears, tomorrow a fresh set go on my Focus at the front i am a big fan and have always rated them as the best of the more budget end of the market. Good tyres, much better in the wet than they are rated and they have an awesome tread pattern

[300bhp/ton]

Curious and I've not looked into it. But the wet weather/surface rating, does this pertain to water dispersal properties of the tyre or is it about it's actually frictional grip on a wet surface, such as under locked brakes or sideways sliding?

[Otispunkmeyer]

300bhp/ton said:

Mossyboy1978 said:

Entitled to your opinion but I can send you the resarch documents that back up the calculations if you like. It's all completely independent and peer reviewed so your argument about smoke and mirrors falls down somehwat.

I agree that the website is designed for the European market whilst the app for smartphone/tablet is Uk specific so the latter will be easier to use and clearer for you. However, if you check the top right of the web version there is an option to switch to UK measurements which might make it easier. It is absolutely worth a download of the app though (free) just to try the better experience of the device-based version.

And I'm intruiged at what science you expected to see. Given your comments are all about the site being too complex did you really want to see the three page formulae that powers the whole thing?

Maybe I was being a bit hard tbh.

In terms of science, well a little expansion on the different categories would have been nice and if you are claiming 30% differences in mpg something to actually back this up rather than just some meaningless numbers that change due to an on screen slider.

I'd like to read the report at least if there is one. Has it been published in a journal? hopefully our Uni is subscribed so I can download it. Wouldn't mind seeing the methodolgy and some results in graph form.

[Mossyboy1978]

Otispunkmeyer said:

300bhp/ton said:

Mossyboy1978 said:

Entitled to your opinion but I can send you the resarch documents that back up the calculations if you like. It's all completely independent and peer reviewed so your argument about smoke and mirrors falls down somehwat.

I agree that the website is designed for the European market whilst the app for smartphone/tablet is Uk specific so the latter will be easier to use and clearer for you. However, if you check the top right of the web version there is an option to switch to UK measurements which might make it easier. It is absolutely worth a download of the app though (free) just to try the better experience of the device-based version.

And I'm intruiged at what science you expected to see. Given your comments are all about the site being too complex did you really want to see the three page formulae that powers the whole thing?

Maybe I was being a bit hard tbh.

In terms of science, well a little expansion on the different categories would have been nice and if you are claiming 30% differences in mpg something to actually back this up rather than just some meaningless numbers that change due to an on screen slider.

I'd like to read the report at least if there is one. Has it been published in a journal? hopefully our Uni is subscribed so I can download it. Wouldn't mind seeing the methodolgy and some results in graph form.

Hi - feel free to PM me and I'll send you the reports. Unforutnately, they were developed by the University of Munich so they are in German but a quick translation using Google will sort that out.

[Nick1point9]

Mossyboy1978 said:

RenesisEvo said:

Assuming the same car, I would wager that driving style has a far, far greater impact on mpg than tyre rolling resistance. Also, above 40-50mph, rolling resistance becomes secondary to aerodynamic drag in terms of what the engine has to overcome to maintain forward motion.

Was the data normalised for contact patch area? (eliminating variables such as axle load, tyre size, etc?)

Actually - research shows that tyres account for between 25 and 30% of fuel consumption - most of which is just break rolling resistance.

Good point about speeds above 40mph but the resistance is still there and must still be overcome. Note also that the UK average speed acording to the AA is just above 30mph so most of the nation is dirving below this speed for most of their dricing time,

You are also right about driving style. In the app I sent a link to, if you change this variable it has a profound affect but it doesn't diminish the tyre's impact, just adds to it if you are a more cautious driver.

Not sure about contact patch area. I'll check that our.

I'd like to see the research that says that more than a quarter of the fuel I use goes on rolling resistance.

[Prof Prolapse]

Mossyboy1978 said:

Hi - feel free to PM me and I'll send you the reports. Unforutnately, they were developed by the University of Munich so they are in German but a quick translation using Google will sort that out.

What a helpful chap!