Mine's synthetic, what's yours?
So you’re at the bottom of a 60 degree climb, having only got half way up due to a wet surface dotted with tree stumps the first time... you consider your options:
Do I need diff locks ?
Is it straight enough for diff locks even ?
Do I floor it and trust to Allah ?
Or do I take a more reasoned approach as it says in the text books - slowly slowly catchy monkey ?
But what about all these people watching - waiting to clap when I succeed or think that they could have done it when I don’t
Sod it ! Your right foot slaps the floor - you’re trusting to Allah...
Just a minute..... just a minute... lets take time out and consider what's happening just under your backside - apart from having contractions of the sphincter.
How many horses have you got ? And what about all that talk / torque ?
Do you know that there are only between 1 and 3 teeth in any gear set that are taking all the load from your right foot and that load equates to about 4 tonnes per tooth, ( about the same force your dentist last used when removing that wisdom ), each tooth in your transfer case and axles are trying to push their way through its partner, its partner is trying real hard to pass on the load without;
or having it’s driven face scared for life
You may think that gearbox teeth are smooth but look at them under a microscope and you’ll see more hills & valleys than in the whole of Wales - as the peaks of the hills pass across each other they actually form a weld and then are torn apart to weld to the next peak (boundary lubrication site) - the actual time this action takes is nano seconds - whatever that means.
You’ve probably already guessed that I’m talking about wear - no not that nice sparkled glittery thing you wore to the last club dinner - but the action of two steel surfaces being passed across one another under high load. The only thing that is going to help to prevent premature or catastrophic failure to your nice, but not so clean machine, is oil - that dark messy stuff that you never give a thought about until there’s a big pool of it laying where it shouldn’t be.
Lubricants are made up of base oils- refined and purified from crude oils, which are then blended together with additives - the type and quantity of additives used will depend on what you want the oil to do. A engine oil may have the same base oils in it as a gear box oil but the type of additives used in it’s formulation will be different because of the environment that the lubricant has to perform in.
I’ve still got your off-roader at the base of this 60 degree climb with your foot to the floor in freeze frame - so I’ll keep this short.
The higher the quality of the ingredients of your oil, both the base oil and additive package the better the performance or it’s ability to reduce wear. Synthetic oils are superior in supplying additives to the point of wear and are better in putting up with boundary lubrication conditions or shear than standard mineral based lubricants. They will keep a thicker layer of oil between your teeth as you go like a bat-out-of-hell up the 60 degree climb and you say to the guy at the top gate with a dropped jaw - “mine's synthetic what's yours ?”