Confusion at Carguide Magazine

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Nov 6, 2002
Carguide, a Canadian magazine, posted the following winter maintenance tip in their October 2005 issue:


Use a low-viscosity oil, ideally a 5-W-30 [sic], which is thinner or runs more freely at low temperatures, and thickens somewhat as the engine (and oil) heats.

So I shot them a quick e-mail, which they published in the February 2006 issue:


Please note that oil thins as temperatures increase (Winter Prep, Oct. '05).
Also, a more ideal motor oil than 5W-30 for most Canadian winters is a 0W-20, 0W-30, or 0W-40, depending on manufacturer recommendations.

Their response:


Raw oil thins as temperatures rise. In order to protect an engine at startup, the oil needs to be thinner when cold so it flows freely. Viscosity modifiers are added to the base stock to make the oil flow better when cold, without making it too thin when hot.

I'm pretty sure they're standing by their assertion that the "W" means that the oil thickens as it warms up!

You might want to restate that and say, run a low viscosity oil for easy starting that resists thinning out as the temperature goes up. Multigrade oil does not get thicker. To make things a bit easyer, look at the kinematic viscosity in centistokes (cS). At 100C (warm) your 5w-30 oil might be 10cS and at 40C (cold), maybe 50cS. You can now see that the oil does not get "thicker" as it warms up.
Well it sounds like they are weasel wording it to save face.

Key weasel words:


without making it too thin when hot.

They are not exactly saying the oil gets thicker. You won, they save face.

NEVER trust this publication for lubricant advice. Unless they hire an "expert"

Ah the guiding press is so often wrong.
"Viscosity modifiers are added to the base stock to make the oil flow better when cold..."

Horsepucky! Those morons don't have a clue. You can't make "thin" out of "thick" with VIIs. (I suppose you could by pouring kerosene into the motor oil...) At best you can only prevent "thin" from overly thinning when hot through the use of VIIs. There's nothing inherently wrong with being clueless. The problems arise when the clueless reach a large audience with their ill-considered drivel and refuse enlightenment when respectfully offered.
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