OEM tires more efficient than same aftermarket replacement

[MetroMPG]

I know this has come up before, but just wanted to add this to the forum for posterity:

On new cars...

...apart from California, [low rolling resistance] tires aren't required in North America, although they're used voluntarily to help achieve fuel-efficiency standards.

That means original-equipment tires tend to have thinner sidewalls and shallwoer treads than replacements.

From Canada, Europe develop tire ratings to reflect fuel efficiency

Also of note, repeating what has been said elsewhere on the forum:

To put things in perspective, on average, new conventional tires have 20 per cent more rolling resistance than worn ones. So when you replace your tires, your fuel economy drops by as much as four per cent.


It's not yet clear whether the same applies to low-rolling-resistance tires. But, in general, they at least start with better efficiency.

[thatguitarguy]

I tend to think that tires with thinner sidewalls and less tread are going to be cheaper, and that's more of a motivation for the manufacturers to install them than to be "environmentally conscientious".

To me "eco" driving is more about being "eco"nomical than "eco"logical. If the tires have less tread, they aren't going to last as long and with what I have to pay to have tires installed and balanced, it seems that any money saved on fuel will be spent on tires.

I'd like to find a set of summer wheels to install some high mileage dry weather tires, but here in the high mountains, weather can change at any time of the year, and you really do need that tread in order to safely get around.

[wagonman76]

Originally Posted by thatguitarguy

I tend to think that tires with thinner sidewalls and less tread are going to be cheaper, and that's more of a motivation for the manufacturers to install them than to be "environmentally conscientious"

My thoughts exactly. They're going to put on the cheapest thing possible that meets safety standards. So anything you buy that's not the original equipment tire is going to be better.

[Piwoslaw]

Thinner walls and less tread means less weight, right? So do low RR tires have more rotational mass?

[Old Tele man]

...the OEM Goodyear RS-A Eagles 205/55R16's on our 2009 Vibe have crr = 0.00915 (per NHSTA document), and they've been used as "base" OEM tires on the Vibe since it's original introduction back in 2003.

...not the greatest, but certainly not the worst by far.

[MetroMPG]

Originally Posted by thatguitarguy

I tend to think that tires with thinner sidewalls and less tread are going to be cheaper, and that's more of a motivation for the manufacturers to install them than to be "environmentally conscientious".

I wouldn't accuse (m)any manufacturers of being "environmentally conscious" solely out of the good of their hearts, but don't forget they also have to meet CAFE fuel economy targets, or pay penalties.

As with any cost vs. fuel consumption issue, you can be pretty sure there's a spreadsheet on the bean counter's computer just about tire selection!