LRR tires PDF info - Gas Savers

Jack · 06-13-2006, 02:05 PM

Some good info here:

http://www.greenseal.org/resources/r...resistance.pdf

SVOboy · 06-13-2006, 02:19 PM

Ah, that old thing,

I wish they would do some more testing on the subject, but NO...

civicminded · 06-13-2006, 02:24 PM

Thanks for posting that up -

Looks like my tires are on there, but at a different size

They list the Sumitomo HTR 200 at 185/70R14, but mine are 195/50R15.

I wonder if they only listed that particular size but the basic premise of LRR applies to the whole model line? I would actually suspect that even though the 195 section would be worse that the 50 series sidewall would be stiffer and therefore actually have a lower RRC than the 70 sidewall.

Any thoughts?

katman · 06-13-2006, 02:28 PM

It's a good read but unfortunately it's 2 1/2 years old and manufacturers rarely keep their tires the same. They may keep the same models but change compounds and tread patterns.

civicminded · 06-13-2006, 02:36 PM

Thanks for pointing that out katman -

:gulp: swallows with grain of salt....

95metro · 06-13-2006, 03:01 PM

Slightly off-topic, but here goes:

What I found interesting was the very first factoid regarding 80% or more of fuel energy being lost to friction and other factors (aerodynamics, pumping losses, energy transfer, etc.)

80% - that's huge! So, we lose that much energy using gasoline or diesel, but all these new "enviro-friendly" fuels have even less potential energy so the wastage must soar to 90% and higher with propane, E85, natural gas, and other fuels.

I keep thinking that the extra energy loss, plus processing must offset most of the "cleanliness" of these new fuels.

Matt Timion · 06-13-2006, 04:08 PM

Quote:

Originally Posted by civicminded

Looks like my tires are on there, but at a different size

Sometimes tire manufacturers will make a tire LRR at one size but not LRR at another. It's totally stupid.

cheapybob · 06-14-2006, 07:09 AM

The EPA should establish some sort of Fuel Economy rating for tires sort of like the UTOG ratings so consumers can tell which tire will be most efficient, and be able to calculate whether savings would justify buying a better tire.

SVOboy · 06-14-2006, 01:27 PM

No one will want to give up their precious tax money for testing,

civicminded · 06-14-2006, 03:05 PM

Quote:

Originally Posted by Matt Timion

Sometimes tire manufacturers will make a tire LRR at one size but not LRR at another. It's totally stupid.

That would make sense, as the ones I have aren't on there.

Has anyone seen data that might indicate that a tire with a shorter (stiffer) sidewall might have a lower RRC than a similar sized tire with a larger sidewall?

diamondlarry · 06-14-2006, 06:02 PM

I just received a reply to an email I sent to the TireRack about LRR tires for my car. Here it is. By the way, the size I asked about was P185-70-14.

Quote:

Larry,
BY LRR I am guessing you mean low rolling resistance. The Bridgestone
B381 is used on the Insight Hybrid and is optimized for low
resistance/fuel economy, and it comes in your size. It can handle light
snow, so a winter like last winter they would probably be ok, although
they are nowhere near as good as a true snow tire in serious winter
conditions.

Best Regards,

Ben Rooney | Sales Specialist

katman · 06-14-2006, 07:21 PM

Quote:

Originally Posted by civicminded

Thanks for pointing that out katman -

:gulp: swallows with grain of salt....

Hey what can I say? I was about to post like not even i minute after the original post but the phone rang and all the rest of you snuck in under me!