Are the Bridgestones a LRR tire?
#11
Re: Are the Bridgestones a LRR tire?
I am not an expert, but I believe, Wikipedia Low Rolling Resistance (LRR) tires make less contact with the road, thus less friction and resistance.
Just guessing, but the 'road hugger' tires will give, presumably, better handling on wet surfaces or curves.
A smaller footprint making contact will roll better and longer (thus the better mileage) at the possible expense of handling.
Another link Hybrid Cars.com Low Resistance Tires
Just guessing, but the 'road hugger' tires will give, presumably, better handling on wet surfaces or curves.
A smaller footprint making contact will roll better and longer (thus the better mileage) at the possible expense of handling.
Another link Hybrid Cars.com Low Resistance Tires
The improved fuel economy is acheived when the tire is not distorted (steady state condition) and an FE improvement of 4-7 percent is possible when LRR tires are used. This is acheived by using materials and tread designs that reduce the 'squirm' frictions that result from the tire spreading as it makes contact with the road and then returning to it's original shape when breaking contact.
The squirm has nothing to do with scrubbing, which is what takes place between the rubber and the road. Instead, it is almost entirely from the flexing of the rubber and (mostly) the elastomers in the tire. This includes the binder between the casing, inner (tube) liner and between the casing and tread, all of which flex and absorb energy that must be released as heat. This squuirming friction in conventional tires creates heat that changes the tire pressure over a larger range. Reducing squirm in LRR tires lowers tire friction without loss of road contact, narrows the heat and permits the tire to operate at the more constant pressures that result from a narrower heat range.
The trade-off for LRR tires is not traction. It is cost (they are more expensive to manufacture), and in the case of the earlier ones life cycle because the materials used were softer. Later designs for LRR tires have dramatically improved tire wear and tire life.
Here are a few sources (there are many more):
http://www.michelin.com/corporate/fr...e=PAG_AXE_RECH
http://www.cabot-corp.com/cws/busine...6TruckTire.pdf
http://www.oeconline.org/livinggreen...ofriendlytires
http://sheldonbrown.com/brandt/rolli...e-tubular.html
Last edited by FastMover; 12-03-2007 at 11:12 AM.
#12
Re: Are the Bridgestones a LRR tire?
Both my '07 TCH and '07 XLE-V6 came with Bridgestone Turanza EL400 which have A - A - 260 ratings. FWIW.
#13
Re: Are the Bridgestones a LRR tire?
Huh.... OK, so ignore what I said about the Bridgestones. The site is confusing - they appear to list multiple tires for the Camry Hybrid. interestingly, they list the ER33 as the OE tire for the TCH, although schmidtj got the EL400.
The 440AA rating is however correct for the Michelin.
The 440AA rating is however correct for the Michelin.
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FastMover
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12-07-2007 01:10 PM
bridgestone, camry, heat, hugger, hybrid, life, low, lrr, manufacture, range, resistance, road, roll, tire, tires