Quick question drives, just wanted to settle an argument !! Can you put wagon engine oil in a petrol car without [ZB]! The car?
Dotty D:
Quick question drives, just wanted to settle an argument !! Can you put wagon engine oil in a petrol car without [ZB]! The car?
No!!
Of course you can. Provided it has a suitable viscosity and API rating (e.g. all the Shell Rotella multigrade oils are rated API SM, so are suited to spark ignition engines).
I wouldn’t be putting it in a Moggie Minor or anything else of that sort of vintage.
Why not? Cars of that era were originally designed to use a straight SAE20 or SAE30 oil, and later versions of the same engine used a 20W/50 multigrade. There’s nothing about oil optimised for use in a commercial diesel engine that makes it unsuitable for use in a petrol car engine.
Not sure about the truck v car oil thingy, but I will state that no matter how desperate you are do NOT use car engine oil in a motorcycle! 
Again, why on earth not? (Assuming it’s not a 2-smoke…)
Please don’t start on about friction modifiers making the clutch slip…
ALWAYS ran my older cars on company engine oil for trucks…it was free, and it doesn’t come better quality than that. Especially the ones needing new rings etc. Never had any issues with it.
I think the only difference in days of yore was that diesel engine oil was often classified as a "detergent " oil and it was supposed that using it would cause the engine to burn oil as it cleaned the rings etc.
Not sure that I would use modern engine oils out of context as they seem very specialised nowadays but I admit to knowing little about them.
Roymondo:
Again, why on earth not? (Assuming it’s not a 2-smoke…)Please don’t start on about friction modifiers making the clutch slip…
Motorcycle engines and gearboxes are joined and share the same oil. Bike oil is developed for something called “shear” which apparently gear cogs cause but the usual up and downy and whirlybird around you bits in an engine don’t.
Funny you mention clutch slip though as my race Fireblade suffered from this until I was told by one of the HM plant mechanics to use semi synthetic as opposed to fully as this caused it. It worked.
The much venerated (and often despised) BL Mini, Metro, Maxi, 1100/1300 and 1800/2200 ranges also had gearboxes in their sumps - and they used plain old 20W-50 oil just like their contemporaries. Bike engines which share the oil with their gearboxes do give their oil a harder time due to the shear forces present in the geartrain - The oil does its job just as well, but not for as long. Hence the shorter oilchange intervals on a typical motorcycle. Besides, a proper motorbike has a separate gearbox anyway…
But regardless of all that - with any engine (car, lorry, motorbike, diesel or petrol) you look at the specifications required by the manufacturer and you look at the specs on the oil container. If the latter meet or exceed the former, then it’s fine to use it. Far more important to change the stuff at least as often as the manufacturer specifies.
Older engines which were designed to run on 20W50 or straight 30 tend not to like modern high tech engine oils and their additive ingredients. Some car type modern petrol and diesel engines have very specific requirements eg 0/30 etc. Failures can and do result if the recommendations for specification and drain periods are not observed.
I use the grade of oil in customers’ vehicles that the manufacturer and the oil company advise. I then know that if there is a failure I won’t have the finger pointed at me when it comes to paying for the repair.
There will always be an opposite argument, so you pays your money (or perhaps you don’t! 
) and takes your chance.
Why not?
I run a few different vehicles from classic sports cars to diesel trucks amd cars to modern high performance bikes. Ebay for 15w40, 25 litres for £50 and chuck it in as needed. Never had a problem in many years.
Yes, you can spend mega bucks on super dooper fully synthetic, but is it really worth it?
Paul
Oils nowadays are very specifically tailored to the engines, a large proportion of the oil is not oil, but additives, I wouldn’t put an oil designed for a modern diesel engine in my car, unless it had a modern turbo diesel engine.