As a grill blocker, what is temp max for efficiency

[donee]

Hi gillis-t,

I ran with 70 % lower grill block on the drive home, with the heater on at 70, once the car got to 85 C, and it was stable at that temp +/- 2 C for the pulse and glide route. Outdoor temp was 55 F. Yea, I know - very wierd weather for Chicagoland. The open 30 % of the lower grill was to the far driver's side.

[beach247]

Thanks. I guess I'm safe for now. It's 1C here in Toronto with light rain. Forecast high is 9C.

Originally Posted by David Beale

If I wasn't running with a Scangauge I'd remove the lower rad. blocking when the ambient temps got above 20C consistently. An odd day here or there up to 30C wouldn't make me remove it.

I'd remove the upper grill blocking when temps were consistently above 25C.

Both my grills are fully blocked, though there is an opening in each end, as the pipe insulation forms a hole at each end which I haven't bothered to block. I access the block heater plug through one of those holes.

All this after two years of observation with the Scangauge of course.

This is a "cold car". I'd be VERY surprised if anyone in Canada or the Northern US ever boiled the coolant (other than if something failed).

Because I use one piece of foam pipe insulation for each grill, with two zip ties each, it only takes a minute to install or remove the blocking. So doing that on trips is practical.