Well, I looked up the specs and see nowhere where it claims to be a 45 weight or even anything other than a 40 weight with the help of additives.
It is a 10 weight oil with polymers added to keep the oil from thinning too much when it warms up. And the polymers start to act at about 100*, so having a thinner oil base in a hotter environment is not necessarily a good thing. It causes the polymers to break down quicker and requires more frequent oil changes. An oil that starts life as a higher weight will generally have fewer polymers than an oil that starts life as a lighter weight oil.

As for zinc, it is only used to protect metal to metal wear. If you are having metal to metal wear, then the oil you are using is failing you. Change it. The oil is supposed to protect from metal to metal. Either the oil is not being changed enough, or it is the wrong multi-grade for your driving conditions.

So is a higher zinc content good for your engine. Sure it is, if you don't change your oil at regular intervals and use the incorrect multi-viscosity oil.

 

Now don't go thinking oils high in zinc content aren't good, they are good. The oils you listed are good as well. I just wanted to shed light on a subject I know about. I probably started shedding light in a 'holier-than-thou' attitude instead of just offering additional insight.

 

I LOVE Kendall!!!!

Kendall lube was used in the IMSA Mazda and won many championships back then. I've used it since, during my rotary days, rotaries loved it.

Miss it...no one carries Kendall any longer.

 

No your fine. I am not an internet warrior


Autozone carries kendall and oreilys can get if not in stock

 

This is one of the reasons I do not use nor recommend using a 5w-anything in the summer/hot weather.
The bigger the difference between the bottom and top numbers the more work that oil has to do.
I did a experiment with my old work van one summer.
5,000 mile oil changes at a quick lube.
E-250 with over 200,000 hard miles on it, 5.4L Trition V8.
5w-30, 3-4 qts used per week. (1,000 miles a week average)
10w-30, 2-3 qts per wk.
10w-40, 2-3 qts per wk.
15w-40 diesel oil, 2-3 qts every oil change!
HUGE difference between oil weights.

 

Yep 5w is a joke unless you live in COLD temps

 

thanks for the research.....