Its never happened to me but, if the engine seizes while you are travelling, the drive wheels would lock and you may be unable to knock it out of gear. The power steering would cease almost immediately and you would be unable to turn the wheel.
All hypothetical, of course but at the trial, the prosecuting council would ask you if you were aware of these potential consequences resulting from oil starvation.
I guess the right course of action is to say to the Boss, “Sorry Sir, but I think that this vehicle is a potential danger”
On the other hand, we all have to live in the real world …
It would probally make expensive sounding banging and knocking noises first.
kr79:
It would probally make expensive sounding banging and knocking noises first.[/quoteThat’s what i was thinking. With all the sensors on new lorries it may not even get that far, even my old 2010 tractor will cut the power and flash warning lights and even shut the engine off if the problem is going to cause serious faliure.
Charles
Not only that but if it did seize it’d probably throw the prop or do a half shaft in anyway and only locking the back wheels for a nanosecond. Not only that a man will go into limp mode and cut out before the engine gets that bad as found out by a Turkish driver at our place 
Mind you as a certain bus driver from the West Midlands could tell you himself if he wasn’t inside at the moment, trying to limp a barely-running vehicle along a motorway can have serious consequences if it grinds to a halt and you get hit from behind.
I’ve driven and ridden vehicles when the engine has seized, and been involved in dealing with the aftermath of such failures. They don’t just lock up immediately - rather they slow down and make all sorts of death rattles before gracefully coming to a halt as the bearings etc melt. Once everything has stopped moving, they lock solid. It’s not particularly scary, and you’ll only lose power steering etc if you dip the clutch (on a manual transmission).
FarnboroughBoy11:
I’m watching this thread eagerly… Did he get his 3 drops done? Did the engine seize up? What did the guvnor say?? Ohhhhhh the suspense!!!
Yep. Channel 5 have been on 
GasGas:
newmercman:
Oil is Oil, as long as you get one that’s for diesel engines it will work just fine and you can mix mineral and synthetic too, it will do no harm at allAny engine oil will be better than no oil
In an emergency yes, but bear in mind that some (most) modern trucks (including new Mercs) have a change interval which is stipulated according to the quality of oil used. Diluting the quality of the oil dilutes its protective abilities and longevity, so an earlier change may be needed.
But yes any oil is better than no oil in circumstances where there really is less than the minimum amount of oil in the sump. But if you top up with a large quantity of poor quality oil you would be wise to change it early.
However, if the truck is leased and is going back in two years or whatever, it’s probably not going to be your problem.
As someone stated previously, its better to let the oil fall towards the bottom, then top up, rather than keeping it up to the top mark all the time. It only needs to be between the two marks.
The oil drain intervals are not dictated by the condition of the oil, it’s all done on gallons of fuel used, which is why a lorry on trunking will have a longer drain interval than one on urban work 
The idea being that as oil only becomes no good from the contamination that is a by product of the combustion process, which means soot. The combustion process also involves lots of metal parts going up and down or round and round, so there will also be some wear metals. The heat from the combustion process will also cause oxidation and nitration, which in turn cause an acidic environment in your oil and contribute to premature wear 
The job of the oil in your engine is to hold all of these contaminants in suspension so that they do not cause premature wearing of the moving parts, so the engine computer works out how many gallons of fuel have been used, which will give a rough idea of the level of contamination of the oil and tells you when you should change it
If you were to analyse the oil after each change, you’ll probably find that you’re changing it too soon, as the manufacturers will err on the side of caution for obvious reasons 
Of course oil also acts as a lubricant, but the lubrication side of things is the easy bit really
When you service a Merc you enter a code for the grade of oil you used into the truck’s computer.
It then works out how long that oil will last (ie is it a bog std mineral, or a long drain synth) and makes the calculation you describe accordingly.
The long-drain oils deal better with contamination than the cheap oils: the soot that gets trapped makes the cheap oil thick, like cornflour in a sauce. It flows slower and doesn’t lubricate the engine so well.
That’s true, some oils have longer drain intervals because they can deal with the contamination better than others, just throwing any old oil in the sump is not the thing to do if you want the maximum life from your oil and your engine
Do you think that now people are keeping trucks for longer than they did, they will take more care what oil gets used?
DJC:
If you’re going to portsmouth, take a look at adams morey. They really only do DAFs but a lot of maintenance stuff in there, I’m sure they could get you some oil. It’s just off burrfields road.
Moreys down bottom off m271 you got hardwoods man dealer 5minutes off j2 in totton or pentagons off j11 m27 on your way to Pompey. If he said take it I’d take it I had turbo go years ago boss told me to finish my round as it was local and bring it back to the yard an hour later engines revving its nuts off ■■■■■■■ oil out off every seal in the engine spraying out the exhaust and the engine wouldn’t turn off it reved it’s nuts off until I stalled it as turning the key wouldn’t do a thing a few “drops” on the way buck totally ■■■■■■ the truck but he told me to drive it so on his head be it he tried bollocking me and I told him not to even start putting it on me so just get some oil any will be better than none keep the receipts and hope for the best 
GasGas:
Do you think that now people are keeping trucks for longer than they did, they will take more care what oil gets used?
They should do
I spent a lot of time researching oil for a feature I did for a magazine last year. Without exception every oil company recommended using the highest quality oil combined with an oil analysis programme, not only so that you can adjust your drain intervals accordingly, but oil analysis also reveals a wealth of information on the health of your engine, every contaminant in the oil comes from somewhere and the amounts can reveal an impending failure long before you hear the terminal clonk, clonk, bang