Originally Posted by Mitsu_Joe
Originally Posted by SpitFire6
Hi,
20Wx is not OK in any engine from any era that is not worn out. Your engine is. So keep using it or "fix" your engine.
I do not know of "Shannows" posts so can not comment.
So you are saying that you burn oil with 20W50 group 4/5 oils but not 20W50 minerals?
"High HTHS" oils are required for old engine designs? Suggest you rebuild your engine to OEM spec & use a modern oil if you love your car. You appear to love your car.
Group 1 or 2 oils are SH1te, period. End of.
Cheers,
Iain.
The first part is utter nonsense. Sorry, but there is no other way of putting it.
Please back your statements up by factual arguments or they do have little value.
You can not just deem something to be not suitable while ignoring the application,vehicle and the environment the vehicle is used in.
Take a viscosity calculator and play with it for a little bit. Mannol Safari 20W-50 (the cheapest dino stuff you can find over here) has a viscosity of ~ 393 Cst @ 75 degrees F.
Castrol GTX 5W-40 as a benchmark shares that same viscosity at around ~ 40 degrees Fahrenheit. Using a 5W-40 grade at that temperature will surely not result in greatly increased engine wear.
Especially on older engines that were designed to run 10W-40 or even 15W-40 oils in freezing winter temperatures when they were new.
If temperatures rarely dip below 50-60 F it is completely safe to use a 20W-50 oil if the owners manual allows it.
Just to give you a relation:
How high is the viscosity of Castrol GTX 10W-40 oil at 14 degrees fahrenheit for instance? 2556.59 Cst...
20-30 years ago, nearly all cars here ran on 10W-40. Also during winter, with temperatures going as low as -10 F.
In 2014, we sold our old car that always ran 10W-40 (built in 1996) with ~170k miles, the engine still ran perfectly and without oil consumption while the rest of the car was basically falling apart.
If you want to cross-check anything I said, look at the corresponding data-sheets and a viscosity calculator of your choice, the data is all out there...
Hi,
So you are saying the Mannol Safari 20W-50 has a viscosity of ~ 393 Cst @ 75 degrees F. Higher than the other quoted oils?
Also, much higher than all your other oils at lower than 75F?
How many cars are started at 75F?
Many thanks for clearing that up.
Cheers,
Iain.