Oil weight vs pressure
Drifting
Joined: May 2006
Posts: 1,428
Likes: 7
From: Chewelah Wa
I run Valvoline dino/synthetic mix. It is not a whole lot more than dino oil. I have done the math on straight syn oil, and you are right, you could by a new motor down the road with the savings. I run 10-40.
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
Some good stuff in your post....until you get to the info above. Assuming operating temps are controlled (via thermostat, radiator, waterpump, and fans), then running temps should be equal in winter or summer, right? So, why would anyone need heavier weight oil in hot weather?
Then there's the snake oil. There's been SO many negative, disproving posts about this stuff (and Slick50, ZMax, etc...), I have to wonder how/why any reasonable mechanic would support it.
It's my understanding that overall improvements in oil, refining, detergents -- combined with ring AND manufacturing technology have led to the remarkable increase in engine life. Nowadays (since the turn of the century), I'd EXPECT any motor to run 200k miles. It wouldn't surprise me to learn that thinner rings, changing in oiling (dry vs wet), precision in manufacturing, and ring pressures may extend the life of a bottom end to 500k (or more). (Can they bore the newer 2k blocks smaller amounts for reuse? Say ten vs thirty thousanths?)
OTOH, I don't expect the avg car owner to be smart enough to do maintenance as they should.
Then there's the snake oil. There's been SO many negative, disproving posts about this stuff (and Slick50, ZMax, etc...), I have to wonder how/why any reasonable mechanic would support it.
It's my understanding that overall improvements in oil, refining, detergents -- combined with ring AND manufacturing technology have led to the remarkable increase in engine life. Nowadays (since the turn of the century), I'd EXPECT any motor to run 200k miles. It wouldn't surprise me to learn that thinner rings, changing in oiling (dry vs wet), precision in manufacturing, and ring pressures may extend the life of a bottom end to 500k (or more). (Can they bore the newer 2k blocks smaller amounts for reuse? Say ten vs thirty thousanths?)
OTOH, I don't expect the avg car owner to be smart enough to do maintenance as they should.
As far as why a heavier oil in summer...its because I've spent most of my time in the SW of the country where the LOW temp for the night never dropped below 100....Or it might be 18* in the morning in winter...5wt was required for those winters and that was too thin for summers with the higher than avg normal temps. The dessert can be brutal on car engines.A temp swing of 50-60 degrees from day to night was common in some places. Thats tough for any multi-viscosity to have to cover that range.
The extremes is why I will use different wt in summer/winter.
In the Az summers the car would stay warmed up for 3-5 months out of the year so I wanted to start with something that was more where I wanted to be at normal temps...Almost an arguement for a single wt oil like a straight 30, but I thought that to be too heavy for start up. Because I'm willing to start up and idle until it (coolant temp) breaks 100* before I move, I'm ok with start up circulating a 20-30 wt when its "cold". In 115* ambients where the road surface is 140*..thats where the 50wt comes into play. Its unavoidable...when its that hot outside...the oil inside holds heat longer. Your water might cool down a bit but the oil being thicker will hold heat much longer and has a harder time exchanging that heat away. I also run a separate trans cooler in front of my condensor so my nose is loaded with heat. I run syn trans fluid, syn eng oil (seasonal) and take the shrouds apart to clean in there more than I do in the cabin..I'll not have a failure from BS like excessive heatng when it could have been prevented. PM is the deal.
