It is an interesting idea, kind of the reverse of running extra oil in summer. I run my Aerostar 3.0 about 12 oz above the full mark, which is a total fill of 4.75 qts using an oversized filter (FL1A). If I ran it a quart low it would still have 12 oz over the bottom of the fill area (hatchured area of stick), so unless you never check the oil, there is a margin of safety. Also this Aerostar has a low oil light.
The real question is whether it does any good. Less oil, the oil should warm up faster. We know that the engine can be at operating water temperature long before the oil is to full operating temperature, so there may be some benefit to his, although running a thinner oil should achieve the same, or similar effect. This (running a quart low in winter) may be an option for someone who does not want to run something as thin as a 5w20 in their vehicle.
As for me, I am leaving well enough alone and will run the same level winter and summer.
The real question is whether it does any good. Less oil, the oil should warm up faster. We know that the engine can be at operating water temperature long before the oil is to full operating temperature, so there may be some benefit to his, although running a thinner oil should achieve the same, or similar effect. This (running a quart low in winter) may be an option for someone who does not want to run something as thin as a 5w20 in their vehicle.
As for me, I am leaving well enough alone and will run the same level winter and summer.
