[V8] Cold killing gas mileage

[urq]

... is the engine reaching proper operating temp?  I found I had a bad 
T-stat on my '88 5kCSQ because on the freeway below freezing the temp gauge 
was low enough that it was as if I had just started the engine!  The worst 
thing was that the heater didn't work and the windows started fogging up on 
the inside.  If the T-stat seems OK but you want to get the engine temp up a 
bit you may want to try blocking some of the airflow to the radiator ...

Steve B
San Jose, CA (USA)

----- Original Message ----- 

> Well, I'm kinda stumped.  At 60 degrees, I can get well into the low 20s 
> for gas mileage, up to 23.  When it is 20 degrees, like lately, up to 
> about 45 or so, my gas mileage barely pushes 18-19.  What gives?  The air 
> temp sensor "looks" ok, MAF is original, and OXS (3 wire) was replaced 
> earlier in the year.  Those were my three guesses.  Also have replaced 
> G82/83 temp sensors and the one on the back of the passenger side cylinder 
> head.