[sokoloff]

It’s about -3% change in drag force per +10°C change in temp.

[maxerickson]

Which is like the same as 60 mph vs 59 mph.

[sokoloff]

In drag force, yes, but in this case, you are taking the 3% penalty and aren't getting the partially offsetting 1.7% increase in distance per unit time that 60 gives you over 59.

Note that it's 3% per 10°C delta so, for a 40°C swing (say 30°C/86°F summer to -10°C/14°F winter), that's a 12% difference in aero drag force.

[Gordonjcp]

Which is basically nothing.

Opening your window makes far more of a difference.