Q. My oil is black, does it need changing?
A. Diesel engines oil is almost always black due to the soot from the engine so you can’t use the colour to decide if it needs a change.
Q. How often to change your oil?
A. How long is a bit of string?
It all depends on the driving conditions. Rover generally specify 12,000 mile oil changes on the L series. If you do lots of start stop journeys, or have a very sooty/tuned engine then you may be better off changing it every 6,000 miles. If you do lots of motorway mileage then you should be ok with the 12,000 mile oil changes or possibly even longer. I don’t recommend it of course, but my oil gets changed roughly every 15k miles and my engine is on 212k miles and producing more power than standard (about 20% more).
Q. What oil grade should I use?
A. In the UK generally you should stick with 10w40 oils. You can get away with 15w40 but cold start protection will suffer and economy will suffer marginally too. 0 or 5 w 40 oils can be used although oil consumption may increase slightly.
Q. What oil type should I use? Synthetic/Semi-synthetic/Mineral?
A. This is a difficult one. In general terms a suitably specified fully synthetic will provide more protection than a semi and that more protection than a mineral. However more protection may simply be unnecessary depending on the engine and operating conditions.
A couple of rules of thumb that I use are:
Cheap oil changed regularly will protect better than expensive oil that is rarely changed.
Ignore the marketing – Look on the back of the bottle for the specifications that oil has met, sometimes this can give big surprises.
So what do I do? Well in my L series derv I use 10w40 semi synthetic and I change it every 12-15k miles. I usually spend about £20-£25 on oil and whatever the filter costs (about a fiver from memory).
Q. Do you have any tips for changing the oil?
Take the car for a drive first. Oil drains better when it is hot, and also takes more impurities with it. Care is obviously needed with hot oil!
Drain the oil from the sump plug. Many garages use a vacuum to suck the oil out through the dipstick hole, however this leaves all the sludge at the bottom of the sump, not to mention any heavy metal swarf. The sump plug is at the bottom for a reason, to drain as much oil as possible and take all the dirt with it.
Once the oil has started to drain go and make a cup of tea and give it 10 mins or so to drain out.
Best practice is to fill the oil filter with new oil before you replace it, so that the oil pressure gets to the engine straight away when it is started.
Remember to lubricate the seal on the new oil filter with oil and it only needs to be put on hand tight.
Remember to replace the sump plug before you start pouring the new oil in! It’ll make a mess of the drive otherwise!
Don’t overfil the oil.