I sent out a email to all the tire manufacturers seeking information on

[Bill R.]

which models they sell that have the lowest rolling resistance since some articles claim it can make as much as 8% difference on your gas mileage..
I just got a reply from Yokohama, Here it is:
Dear Valued Customer,

Thank you for contacting our offices.



This information is for propriety purposes only. We do not have this information available for your review.



Sincerely,

Consumer Affairs Department

I guess that they don't want to sell me any tires eh?

[bahnstormer]

guess not =]

[Jose]

Worked closely with Japanese, and that´s their approach towards customers, cause, who knows...you might be a SPY !!!!

[SharkmanBMW]

they think you will copy their product somewhere in China!

[Anton CH.]

It bugs me that companies hide their information from customers. Information that customers use to base their purchase on. Rolling resistances can determined via an experiment so really if I was to copy their tire I'd start looking at the tire composition before the resistance. Just try asking H&R for the spring rates or Koni for force-velocity diagrams or any other suspension builder for that matter.

[632 Regal]

their not hiding that information, they simply dont have an answer for the above average person that asks for it. In other words they most likely dont have a clue.

[SRR2]

Someone with a Hunter Road Force machine should start building a database on this.

[genphreak]

Euro car manufacturers buy tyres based on performance and economy. They strike a good balance as performance and economy stats are everything in the buisiness of selling cars there.

Continental are very successful selling tyres to premium buyers such as BMW and Mercedes already as they meet such needs well. Perhaps see what they specify in larger sizes on economy type models. There is a bit of info available on Continental's EU websites such as this UK one, perhaps other euro manufacturers' sites such as Michelin's and Dunlop's too. People in europe have been asking the kinds of questions you are considering decades years ago and buying 600cc vehicles instead of SUVs.

(Don't waste your time on US sites, the market in Europe has been dealing with high oil prices and the costs of pollution that America has been ignoring and exacerbating for years).

Don't expect a world of choice in economy tyres in 7 and 8" widths though, people in europe have smaller cars so don't specify such fundamentally insance requirements (ie fat and sticky does not in any way equate to low rolling resistance), so most tyres marketed as economical are sold to people with relatively economical cars in the first place...

GP

[632 Regal]

UK tires are not D.O.T. approved for use in the US so that information is only good for the UK users.

[genphreak]

UK tires are not D.O.T. approved for use in the US so that information is only good for the UK users.

I'm not talking about UK made tyres, just info available on EU sites. Conti, Michelin and the other multinational manufacturers generally get each of their new tyres types DOT approved; the US market is pretty important to them and they cannot fit them to production cars unless they are.

There are exceptions- especially in the smaller sizes that are not sold there, but we're not talking about them in e34 sizes.

Its a good point this thread though- in the same way the end-user is effectively restricted from performance info on fuel injection components, I suspect the tyre companies prefer to talk figures with the car companies only, leaving conusmers to get reamed by their typically product-ignorant marketing departments. (Then again, maybe they just give the manufacturers new tyres models and let them do the testing as part of the procurement cycle (I doubt its that simple though...) GP