Originally Posted By: OldEuroCarLover
I've been using this oil to help with consumption, and recently did an oil change and used it. Is it okay to leave a 10w oil in the car over winter? It's gone to -10f a few times here in NJ. Usually, it's coldest from January to early March. Should I change it out around December, regardless of miles? Or is it okay to leave it in?
A 10W is probably OK for a minimum temp of minus 10f. If you look up the pour point in the oils product data sheet, you will not get any significant extra wear during cold starts until the temperature drops below 10c above the pour point.
YEABUT some might say, using a 10w40 in winter is kind of tough on the battery, starter motor and alternator. It will also result in higher fuel consumption than using an 0w40 (Or even an 0w30 if you are a thin oil fan).
I would just use Mobil 1 or Ultra 0w40 all year AND add half a can of Liqui Moly Motor Oil Saver (It's a stop leak additive).
When selecting an oil it's a good idea to use the oil finder or guide page of the oil company web site as a cross check against the owners handbook. It can be very important to use the correct API (Or Acea) spec oil for some engines, as you can get real bad long term results using a DPF approved low ash oil in older engines in particular.
I'm not a real fan of HM oils if you do not have any oils leaks that are beyond economic repair.