The colder it is outside, the more my gas milage drops

[Zenmervolt]

Originally posted by: Jahee
I see your point, but in this case, the driver would use less throttle because for the same throttle he used in summer conditions, it would accelerate more, so to keep the same acceleration, they would use less throttle in winter? reducing the air intake and therefore the fuel injected?

Edit: Also i didnt realise additives had that much effect on a fuel + mileage? is it that big?

In general, we're not talking about enough of a power increase for the driver to feel, so the driver is not likely to actually use less throttle in practice. Also, if we really get into it, the less throttle the driver uses, the less efficient the engine is because it is "wasting" power by having to suck air past the throttle butterfly. The less throttle used by the driver, the more restrictive the throttle butterfly is and the harder the engine has to work to breathe, so even though the driver would theoretically be able to make the same power with less throttle, the engine would still be using slightly more gasoline due to the inherent inefficiencies introduced at smaller throttle openings.

As far as the winter blend goes, a 2-5 mpg drop is considered normal in the winters in the midwest. I cannot say for sure how much of that is the winter blend, but it is always listed as one of the larger factors (judging from the relative size of the other factors, it seems reasonable to say that it is the largest factor).

ZV

 

[Zenmervolt]

Originally posted by: Electric Amish
What about this theory:

During the winter I run the defroster a lot, but in the summer I rarely use the A/C. Since they use the same compressor causing drag on the engine it could account for the lower fuel efficiency.

That only applies to newer cars where the defroster is linked to the A/C.

Personally, I pull out the A/C clutch relay in the winter because I dislike having the A/C come on with the defrost and I've never had a situation where I needed the A/C to de-humidify the air.

ZV

 

[Zenmervolt]

Originally posted by: eelw
🙁 Sadly my Civic Hybrid is going through this. I can get over 1,000km on a tank of gas during the summer. But now, I'm only getting 700km. And it will get worse as we get more snow storms in the next couple of months.

Hybrids are more affected by cold weather because batteries lose a large amount of power when they are cold. (OK, so they technically don't "lose" it since once they warm up they have it again, but they are incapable of delivering it, let's not get too technical on this.) Since the batteries aren't delivering full amperage in colder temperatures, the gasoline engine in a hybrid has to do a lot more of the work.

ZV

 

[Zenmervolt]

Originally posted by: KK
Changing the thermostat is going to be a pain in the ass, at least it isn't stuck closed.

Had that happen to me once. In summer. Had to drive home with the heater on full blast to keep the car from overheating.

ZV

 

[shortspanishguy]

Originally posted by: eelw
🙁 Sadly my Civic Hybrid is going through this. I can get over 1,000km on a tank of gas during the summer. But now, I'm only getting 700km. And it will get worse as we get more snow storms in the next couple of months.

My hybrid is doing the same.