On 07/19/2017 01:51 PM, Mad Roger wrote:
This Consumer Reports report says that the OEM tires are designed for fuel
efficiency where the replacement tires can have a few mpg impact, so, that
seems to back up the claim that too many things change even if all you do
is change the tire diameter.
http://www.consumerreports.org/cro/n...nomy/index.htm
"Consumer Reports recently tested a few all-season tire models with low
rolling resistance and found that those tires can improve fuel economy by
an additional one or two mpg."

LRR tires can also significantly reduce tire life. As long as the
manufacturer can boost the CAFE numbers with an OEM LRR tire they are
not concerned with the tire life. Replacement LRR tires tend to be more
expensive than other options. Given the current gasoline prices I'm
willing to give up a couple of mpg for better life and handling
characteristics.