Winter Misconceptions

[john1701a]

Just like the HIGHWAY misconception document, I'm diving into details about stuff we often encounter as owners... which often ends up in frustration, because some either don't simply understand or are intentionally attempting to mislead.

http://john1701a.com/prius/prius-mis...ons_winter.htm is where you'll find it.

Comments & Suggestions are welcome. (Thanks!) Like all the other documents, I expect routine updates as the need presents itself.

[chuck_k]

You have a serious typo in the "Starting" section. Spell check won't catch it.

Less energy can be extracted from fuel using cold air as warm. [/b]

Ummmmm.....I wouldn't phrase it that way. The same energy is being extracted from the fuel--that is, the fuel has the same energy to give--but the air is denser when it's colder, so a stoichiometric ratios the denser air will require more fuel for the same volume of air.



As for "Tire Upgrades," Nokian WR is a superior tire with superior winter performance at virtually no penalty in summer. There is no better all-season tire out there, and there is NO other all-season tire with the winter-service snowflake emblem to denote its rated capabilities.

Frankly, I find it disturbing that people have gone through their driving lives without once noticing or being told that they get fewer miles per gallon in winter than in summer. This is Driving 101. And of course, ANY car that uses gas will experience that phenomenon.

Maybe that's why people are confused--they think they're driving an electric car. They're not. They're driving a pure gasoline car. As such, it is subject to the same weather effects as any other car for which the sole source of energy is gasoline.

[usbseawolf2000]

Under "Starting" section:

Using that substantial power advantage, the engine is spun to idle speed (between 800 & 1000 RPM) then maintained electrically until oil pressure is established. Following that, fuel & spark are not initiated.

I do not believe the "Not " belongs there.

[dogfriend]

In the Starting section,

Following that, fuel & spark are not initiated.[/b]

I think you actually meant fuel & spark are initiated.

Edit: Usbseawolf beat me to it while I was talking to a coworker. I do have to work sometimes.


Also, I agree with Chuck about rephrasing the part about cold air. Cold air is more dense as he said.

I think that a significant part of the drop in efficiency in cold temps is that the lubricants (not just engine oil, but trans fluid, differential fluid and wheel bearing lube) don't flow as well and the clearances are less between parts.

[usbseawolf2000]

The NiMH HV battery pack (201V) has about 1,450 equivlaent CCA if drawn at 12V. That's more than twice the power of a lead acid battery to start a small 1.5 liter engine.