Winter mpg penalty
 

After driving my Civic DX for about a year with a scangauge, I'm able to achieve 40mpg fairly easily now on my commute. In the winter when temperatures are from 0 to 35F, I have a hard time getting better than 36 mpg.

What's the best first steps to help this?

A block heater is a good start during the Winter months. It's on my "to-do" list.

Don't use any power hungry and heat-robbing (cabin heater) accessories during warm-up. The engine needs all the heat it can get during the first few miles.

People tend to idle in Winter to warm up the car. Not only does it uselessly consume a fair amount of fuel, it can lead to excessive wear of key components of the drive-train on the long run and the emissions (pollution) are very high due to the rich mixture and because the catalytic converter is not yet at optimum operating temperature. The most efficient way to warm up the engine is to start driving 20-30 seconds following the initial ignition.

A block heater is a good start, a fuller grill block is another good one. Basically anything to get the engine warmer faster. Of course, you still can't avoid some stuff like the denser air aero penalty.

Thanks for the tips. It shouldn't be hard to watch water temperature and only turn on the heater when it's up to full temperature.

I've heard of people routing the air intake so it runs near the exhaust manifold so the air is warmed up, sort of an anti-intercooler. I wonder if that's possible on the Civic.

pre-heat your fuel. i've done it to my 94 and 98 Metros. I did it 2 different ways. 1. copper tube wraped around the lower radiator hose. 2. Used the cooling lines on a radiator for an automatic.

Agreed -- the radiator/grille block and engine block heater are both great options in which to start. Depending on the vehicle, sourcing warmer air could help (most during startup, but varies between vehicles for closed-loop operation).

A short ram air intake on ebay should do the trick or not running your heaters till the car warms up an alternative is to buy a set of plug in heated seats for your car and plug them into your cigaret lighter leave the car in access mode in the morning let them warm up then start and drive off.

Don't drive during the winter. :p

Seriously tho, there isn't much you can do about cold weather. If you use a block heater it is costing you in the energy to run it. I have both a grill block and a (removable) full radiator block, but it still takes time for that initial warm-up to occur and the gain from that strategy is minimal at best.

The best strategy is to avoid short trips where the vehicle never comes up to full operating temperature. It's easier said than done, however. Some of us have no choice, depending on where we need to travel. At sub-freezing temps a car cools off really fast; then it's "back to square one", unfortunately.

a short ram intake will work best once the engine bay is mostly closed off, which will keep more heat in the engine compartment. If the car is kept in a garage i would get an AC adapter that those seat covers could plug into so you aren't using battery power (that the alternator will have to replenish), until you get into the car and start it