Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - When does having your windows down start to effect your mileage?

donee · 03-08-2008, 08:05 AM

Hi Chris,

Not too sure if there is any effect with those visors, other than the effect of the visor itself (with the window up). I have on occaision in the summer reduced fuel consumption by tuning the amount of opening of the down wind rear window opening. The amount of opening is only about 1/4 inch or so. Any larger than 1/2 inch makes worse mileage.

This is easy in the Prius as they all have power windows and the fuel economy display. Typically, the difference is about 5 mpg in the Prius when running down the road at 60 mph into a steady 10 to 20 mph off-center head wind. So like from 50 to 55 mpg.

The concept is to inject air into the zone where flow seperation might begin due to the off-center flow.

03-08-2008, 08:05 AM	#2 (permalink)
donee EcoModding Apprentice Join Date: Jan 2008 Location: Chicagoland Posts: 204 - - '10 Toyota Prius III w/Navi Thanks: 4 Thanked 12 Times in 12 Posts	Hi Chris, Not too sure if there is any effect with those visors, other than the effect of the visor itself (with the window up). I have on occaision in the summer reduced fuel consumption by tuning the amount of opening of the down wind rear window opening. The amount of opening is only about 1/4 inch or so. Any larger than 1/2 inch makes worse mileage. This is easy in the Prius as they all have power windows and the fuel economy display. Typically, the difference is about 5 mpg in the Prius when running down the road at 60 mph into a steady 10 to 20 mph off-center head wind. So like from 50 to 55 mpg. The concept is to inject air into the zone where flow seperation might begin due to the off-center flow.