Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Talking to a Bridgestone engineer tomorrow

Frank Lee · 09-02-2009, 12:18 AM

I have some:

1. I was really happy with the OEM tires on one of my Fords, yet when it came time to replace them they were UNAVAILABLE to anyone but OEMs.

I have been relatively disappointed in my subsequent replacement selections.

I have since learned that oftentimes OEM tires are NOT available as replacements. The OEM tires often (always?) have better r.r. than what the tire shopper can get.

Why not fix this absurdity?

2. Is optimal contact patch geometry for lowest r.r. "square" i.e. same width as length? If my observations are correct, typical OEM tire sizing results in patches that are longer than wide. If the above postulate is true, would skinnier tires actually make r.r. worse?

3. What would your professional advice be to the serious hypermiler who wants to reduce r.r.? Is there a difference between "on the record" advice and "off the record"?

09-02-2009, 12:18 AM	#2 (permalink)
Frank Lee (: Join Date: Jan 2008 Location: up north Posts: 12,762 Blue - '93 Ford Tempo Last 3: 27.29 mpg (US) F150 - '94 Ford F150 XLT 4x4 90 day: 18.5 mpg (US) Sport Coupe - '92 Ford Tempo GL Last 3: 69.62 mpg (US) ShWing! - '82 honda gold wing Interstate 90 day: 33.65 mpg (US) Moon Unit - '98 Mercury Sable LX Wagon 90 day: 21.24 mpg (US) Thanks: 1,585 Thanked 3,555 Times in 2,218 Posts	I have some: 1. I was really happy with the OEM tires on one of my Fords, yet when it came time to replace them they were UNAVAILABLE to anyone but OEMs. I have been relatively disappointed in my subsequent replacement selections. I have since learned that oftentimes OEM tires are NOT available as replacements. The OEM tires often (always?) have better r.r. than what the tire shopper can get. Why not fix this absurdity? 2. Is optimal contact patch geometry for lowest r.r. "square" i.e. same width as length? If my observations are correct, typical OEM tire sizing results in patches that are longer than wide. If the above postulate is true, would skinnier tires actually make r.r. worse? 3. What would your professional advice be to the serious hypermiler who wants to reduce r.r.? Is there a difference between "on the record" advice and "off the record"? __________________ Last edited by Frank Lee; 09-02-2009 at 12:27 AM..