Anyone do this? I removed mine last year to get warmer air in these below freezing temps. Cant say if it helped or hindered. I would normally not on a car with electric fans, but the viscus fan runs all the time, so I am pretty sure air intake temp is not near ambient engine temp.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

Its winter. So bumping! Just curious. I have been running without mine for about a month now. No change at all in economy, so I can not say if its been helping or hurting. I do know that on a Euro, this is NOT something one would want to do. Just for a U.S. car.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

On my 91 / 92 Jettas there was a thermal valve on the side of the airbox which would draw warm air from behind the engine when it was very cold out. If it's below freezing I would leave them off, or redirect them to the front corner of the engine bay so they get cool but not freezing air.

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

My 73 Lincoln had something like that. It had one large intake tube for the 7.0 engine. Under the tube was a large flap that would open or close based on engine temps.

I should install an air intake temperature sensor to monitor things.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

It would be interesting data!