I meant to say changing oil & filter *regularly*
Absolutely jimboy! Renewing engine oil AND FILTER on a regular basis (at least once a year if you're not doing the mileage) is probably the single most beneficial thing you can do. Apart from the normal degradation which takes place as an oil ages, it also accumulates contaminants. Some of these will affect its chemical structure, for instance "using up" antioxidants and anti-corrosives, but some will be physical particulates. Modern engines have plenty of constriction points which these particulates can potentially block, for instance, oil jets to cool the back of the piston crown, fine mesh filters on cam variator valve oil supply, feed pipes to turbo's and so on. To say nothing of the strainer on the pickup pipe! Regular oil and filter changes go a long way to rectifying this. I like to change my oil when it's good and hot, after having driven across the city perhaps, as the heat makes it nice and "runny" and suspends most of the particles so they come out with the oil. But care needs to be taken not to burn yourself as it will be VERY HOT! I wear a long gauntlet type rubber glove which gives just enough protection. For these reasons I do not believe in extended interval servicing especially if the engine is turboed, as this puts a lot of extra stress on the oil.
There will always be some solid matter which manages to find a wee corner to "hide away" in, anyone who's dismantled an old engine will testify to that. I would advise against using one of these engine cleaning additives, which you add to the oil, before changing it. Especially if it's an old engine which has not had such a product used on it before. They seem, not surprisingly, to contain a lot of detergent and are quite good at dislodging "crud" precisely because of this there's always the chance a bit of this "crud" will break loose and travel round in the oil until it blocks something up! Better just to let it rest where it's settled in my opinion. If you do regular "hot" oil changes there's not going to be much of it.
As to choice of oil. Well, where to start? After many years of trying to find out I'm still confused. The companies, understandably, want to protect commercially sensitive information. So, I have concluded:- 1. You won't go wrong buying a "big name" (Castrol, Shell, Petronas, Mobil, etc, etc.) product, as long as it meets manufacture's spec. One of these will have been the original factory fill after all! The problem is it's a good way to spend more than you need to.
2. There are a lot of online offers for these big name products and bargains are to be had. I sometimes buy this way but only from suppliers I trust who specialise in lubricants and if I don't need it in a hurry.
3. There are quite a number of "not so big name" products which are very good but cheaper. Names I have experience of are Comma, TradeTEC, and Halfords own branded. Professional motor trade sources, "Factors" will often supply these at advantageous prices and, for standard, every day, motoring are most satisfactory. Halfords trade card opens the door to some surprisingly good prices on Halfords branded goods and very useful on a Sunday when everyone else is shut.
4. I would not go near any very cheap product particularly if it comes from a supplier who is not involved in supplying other motor related items. Could be a bargain, but too great a risk to my way of thinking.
So, make what you will of it all. I'm not at all surprised to hear that some sites ban discussions on oil because it always seems to end up with opinions and "smoke and mirrors" - did I hear someone say Snake oil? Well that's perhaps a discussion for another day!
