Havent posted here in a long time, figured I would show you guys what I did to my DD's for this winter.
Didn't really notice any gains in MPG but it helps a bit with warmup and keeping the engine warm at speed. The subie's have a 180* tstat factory I believe and so it normally runs around 180-185*. With the block it runs more around 195-205 and I noticed the heat is a bit better at that temp, naturally. And with the TDI any heat you can get is better. These things just dont warm up.
Both have the upper grill blocked from the inside, hard to tell on the TDI. The subie's is adjustable in that on either side I can bend the coro back and open up the two outside "squares" of the grill.