l u c a s heavy duty oil stabilizer.
I would not use it myself. It was a good product back in the '70s. but cars & oil have changed. Considering where you live it should not cause any problems other than maybe a very minor reduction in mileage, but it is best to stick with the recommendations in the owner’s manual.
[b] If it was a great idea, it would be indicated in the owner's manual.[/b]