One thing you might consider is a block heater. Since it's so cold, and you're only doing short trips, as another poster noted the engine doesn't even have time to warm-up properly. That means you're running in Open Loop, which is very inefficient, since the O2 sensor isn't controlling the mixture via its inputs to the ECU.
An added Plus is you'll have instant heat. Here's a universal engine coolant heater that you don't install in the block itself, but rather it connects to the cooling system hoses. So likely a much simpler installation. I did find some posts here about the style of heater that takes the place of an engine block freeze plug, and the install sounds a bit "hairy".
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More Information for KAT'S HEATERS 13100
Another, cheaper solution is to block off a portion of the grille, for reduced airflow thru the radiator.
Last year it was so cold in PNW that my Gen I 3.4 (it's a GM V6 swap) Trooper wasn't getting warmed up when I was taking my daughter to work. Getting bad mpg. I just tie-wrapped a chunk of cardboard to block about half the grille, and it made quite a difference. Faster heat, smoother running, and mpg went up quite a bit.
This year I made a nicer wooden block-off panel which covers the entire opening. It has 2 spring-loaded J-hooks to hold it in place. Man, what a difference! Even in 13 degree weather it works very well. The heater gets hot fast and I end up having to turn it down after a while, whereas before I was running full-blast even on the trip home. The Trooper has some big rectangular holes in the valence below the grille, so I expect it's still getting plenty of air to the rad via those. No problems with overheating, even in mid-40's temps.
Looking at your grille, maybe block off the larger upper section. I'd just cut a piece of cardboard to fit and tie it in. Heck, you could just use some small cord in each corner, to hold it in place for the experiment. Or tape it in place, just be sure to use the right tape so you don't get a ton of ugly residue!
See how that goes and if it warms up faster, you're on the right track. You could then block half of the lower section and see what that does.
Last thought, if the rig has a lot of miles, you might consider replacing the upstream O2 sensor. A sensor can degrade and send a "too lean" signal to the ECM, which then injects more fuel. This OE ACDelco sensor at Amazon is probably the cheapest shipped price for an original sensor, if you have Prime:
Buy GM Genuine Parts 213-802 Heated Oxygen Sensor , White: Oxygen - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
Otherwise, check out eBay or Rockauto for similar deals.
Hope that helps............... ed
