With my coolant heater installed and winter approaching I thought I'd do a test similar to MetroMPG's. I plan to test warm-up times both for the heater, and for idling (starting with cold engine) to see the difference. Yes, it's a waste of fuel (and a source of pollution), but it is in the name of scientific research. Plus I'll do it before a planned drive, so that should partially offset any bad side effects.
To make the results as comparable as possible, I'm waiting for temperature to drop to around between -5° and -8°C. In the meantime, I'm thinking about what I need to pay attention to while performing the test. Every 30 seconds MetroMPG took readings of Intake Air Temperature, Coolant Temperature, Fuel Comsumption (in LPH). I plan to note a fourth parameter, either Engine RPM or Total Fuel Used, probably the latter is more useful.
Does anyone have any suggestions? Maybe I should pay attention to something else?
I wonder: Will my engine get up to temp in less, or more, than 17 minutes? On one hand, it's a super efficient turbodiesel. On the other, it's 1.6 liter 4-banger with an aluminum block and 110hp, so there's a lot more going on in there than in a Metro's 1.0. I'm taking bets
One thing I should add is about my air intake. It's not a short, straight-forward affair, but instead partially feeds from the engine bay, snakes around to the air filter behind the engine, then comes back up front to the turbo, passes through the intercooler (no cooling when not moving), and finally enters the manifold. This essentially makes it a WAI when the car's not rolling, with lots of pumping loses. When moving, the IAT is usually 2-4°C above ambient air temperature, but when stopped it grows pretty fast, like up to 50°C (with outside temp around 10°C) in less than a minute. A turbodiesel is more efficient with a CAI, but maybe this won't matter in this test.
EDIT: I just remembered that I recently installed an EGR/coolant heat exchanger, but this probably won't have any effect in this warm up test since the EGR valve supposedly doesn't open when idling.