Over the years, I have appreciated the advice of Diesel Car in helping to choose the right vehicles and how to maintain them. At the moment, in the family we have three Skoda Fabias, all of them with 1.9 TDI engines, and for many years I have used the recommended Millers engine oil. This is a semi-synthetic oil, but I have noticed that my local Asda supermarket now offers a fully synthetic oil, at a price of £20 for five litres. Would this be a better product to use, or is Millers still what you would recommend? Being from Yorkshire, saving money is always a factor, and this fully synthetic stuff seems good value!
Jack Ellsmore

To be honest, whilst the Millers is perfectly adequate, if you want to save some money, then the Asda oils (5W30 and 5W40), which I am told are made by the perfectly respectable firm of Comma, would be a fine enough alternative. I think 5W30 would be the correct choice, unless any of the cars are high mileage and using some oil, in which case 5W40 might be more suitable. I don’t know whether all your Fabias get plenty of exercise, but the only small danger of switching to a fully synthetic oil is that sometimes the extra detergent power of them will shift some gunge that has accumulated in the engine, if the engine has not been worked very hard. So some people used to say that it was best to flush the engine with special flushing oil when you switched over to a synthetic oil. Possibly a cheaper, and equally effective, alternative to this would be to dose your oil with Wynn’s Engine Flush Diesel that costs about £6 for 425ml, and run with this for a few miles before you switch over to the synthetic. But if you have changed the Millers semi-synthetic regularly, I really don’t think on balance that this would be necessary. On second thoughts though, maybe you would do as well to stick with good old Millers. We’ll call it a split decision!
Doc

P.S. Asda synthetic oil specification: This motor oil is suitable for high performance, higher mileage petrol and diesel engines on extended service intervals. Meets or exceeds requirements of the following specifications: SAE 5W30: API SM/CF ACEA C3, Low SAPS/Low ash.