Ive got a Freelander (yes - I know the lists view of these so please spare me!) on a W-plate with 20k miles - its in excellent condition and I want to try and keep it that way, because it needs to provide long service as a staff car for a small business. Its got the 1.8 16v K-series rover engine in.
My local dealer has given me a choice when it goes in this week for a service - which oil! He stocks three types (all Vauxhall branded) - mineral (15/40), semi-synthetic (10/40) and synthetic (5/40 i think).
Having read so many HJ columns and the FAQ, I really want to stick the fully-synth in so hopefully the lump will last, BUT a mechanic mate of mine who works at the local Rover dealer says not to use fully synth on these K-series engines, because it is too thin! Aparently it can lead to (or exasperate?) some of the problems 'occasionally' experienced by these engines.
If you look at previous threads on fully synthetic oil, the general advice is to change first to semi-synthetic and run with this at least until the next oil change. Fully synthetic can act a bit like flushing oil on an older engine and release any crud built up internally which may block small oilways.
I'm surprised the dealer offered 15w/40 oil : this is for older 1980's engines.
All modern engines should be on 10w/40 or lighter oil, ie, 10w/30 or even 5w/30. Your engine will suffer less on cold starting and you will get better m.p.g. Finally, go for a reputable brand such as Castrol magnatec. Smaller blenders such as Millers, Morris's are good, but hard to find : avoid supermarket unbranded oil and compare s.a.e & manufacturer specs (eg Ford) on the back of the can.
Now, I'm not an expert, however, if the synthetic and the semi share the same high viscosity number, then although the synth may *appear* to pour more easily, it will still maintain an equally good film on the bearings etc at high temp and load.
Perhaps the opinion you quote, if there is any basis for it in fact, stems from the advice given by the makers of synth oil that it can be left in the engine for much longer intervals.
I don't think any of these manufacturers would advise against its use in any car engine that's in good condition, but maybe their hype about it's longevity should be ignored, and the oil changed at the usual intervals. hth.
Generaly 5W-40 oils are a little thinner than 10W-40 mineral base oil at 100 deg c. However, this differnce will be minimal. The synthetic oil should have a far higher viscosity index etc so will provide far better protection, particularly on a cold start where it will be far less visous than a mineral base oil. If you still think the 5W-40 will be too thin, why not try a thicker full synthetic like Valvolene's 5W-50. Its cheap too.
I have heard that synthetic oils become less desirable if "stretched" to too great a viscosity range.
Apparently to achieve a very high viscosity potential on a synthetic which starts off "thin" at ambient temperature, undesirable thickeners have to be added which have a tendency to impact on the oil's stability. The Valvoline may not be the ideal choice, therefore. The same if not more so also applies to conventional and semi-synthetic oils
This is true. It will have a significant number of viscosity improvers. But then so will oil like 0W-40 mobil 1. I have herd from people who have their oil analysed and run Mobil 1 for over 10k between changes with no serious oil degredation. An oil with no viscosity improvers will be best for steady state condition, but these are not normal conditions for road cars.
I think the benfits of the 5w-50 Valvolene oil far outweigh the costs. I dont think the viscosity improvers will be an issue at all if normal drian intervals are maintianed- ie less than 5k miles.
If you dont mind paying, Redline 15W-40 would probably be great in that engine, and you may be able to go up to 15k miles between oil changes- but its expensive.
All (multigrade) oils contain some VI improvers. Generally full synths have less of these compounds because the purer molecule chains used have a flatter viscosity vs temp curve than do minerals (remember a semi synth is still around 50% mineral).
I would err away from fitting any oil that is thicker than that specified. This engine is designed for a 10W40. If you fit an xW50 then this oil will be thicker at normal sump temps (c80 degC) than an xW40. This means the pump is having to work harder to push the oil around the engine - this will cost you fuel. Also tight clearances such as big ends and main bearing will be set for a SAE40 oil, so a SAE50 may struggle to pass through these clearances. Also the oil will not flow so easily to non pumped areas. Provided you only drive in the UK where ambient temps rarely exceed 30 degC an SAE30 should be OK but going the other way ie a little thinner and may save you some fuel.
For the same reasons steer clear of a 15W - this will be thicker at 0 degC than 10W and harder to pump - again costing you fuel and not getting around your engine so easily after a cold start. Again 0W or 5W will be better in this respect, though it never gets cold enough in this country for us to take maximum advantage of these grades (in some areas of the world, starting an engine at -35 degC is common).
Since its longevity you are after, then whatever your choice of oil also consider your service regime and driving style. When you start up allow the engine 10 seconds to get the oil moving before driving off and drive off moderately for the first 3 - 4 miles to allow the engine to warm up - remember the oil temp does not rise anything like as fast as the water temp. At the end of a hard slog drive the last few miles moderately and allow the engine to settle at idle before switching off. The service interval for this engine is 12 mths or 15k miles (in the Rover 45 anyway) - Consider an oil change every 6mths.
Don't forget all the other fluids in the car too. Make sure you follow the service regime for antifreeze and brake fluid. Even though no changes are specified for PAS or gearbox lubricants, consider changing these at 3 -5 year intervals anyway.
Red Line do a 10W40. In the UK it's even more expensive than Mobil 1, but it is a very good oil. Have a read up on viscosities and synthetics on the Red Line, Torco, Amsoil and Mobil 1 websites (or consult a fluid mechanics text book in a University library).
Re: Freelander user report please Andy. -
Thanks for all the advice guys - Im going with my original thoughts (and, thankfully, those of my mechanic and you folks) to use the Vauxhall GM semi-synth stuff. Glad you all rate it - this guy certainly does, he uses it (and the fully synth) in everything.
Dave, I will definitley post a report on are 'lander - just as soon as Ive got 5!
Thanks again guys.
BTW, reading the HJ car-by-car, I see that he lists the thing about re-torquing the head bolts, but having read recent posts about a rover 200 I guess this too needs to be changed...
Engine oil has a much higher viscosity at 0C than at 100C. If you use a 0W instead of a 10W then at the moment of start up the 0Ws viscosity is roughly the same as the 10Ws would be after being warmed up by 10 to 20 degrees. What this means is that in the winter the 0W flows around your engine much quicker at startup protecting all those vital components sooner.
Once your engine is fully warm and the sump temp is around 80 deg C then any 40 weight oil must fall into an industry standard viscosity band (or tolerance if you like). So whether you choose 0W40, 5W40 or 10W40, once warm they will all be in the correct viscosity range for your engine.
If you want further reading on the whys of using fully synth then have a look at the technical data pages on the Red Line and Amsoil websites.
If you want a personal recommendation: I have a 97 Rover 820 Vitesse Sport (the 200 bhp version) with 112k on the clock. It was fed a diet of mostly Mobil 1 (0W40) up to 88k (when I bought it), Halfords Fully Synthetic (5W40) for the next 18k and Castrol RS (0W40) since. I have enough Castrol RS to last me another 18k in the garage. The car drives like new, can slightly better the performance figures given by Autocars test of this model in 1994 (in an event for Revs magazine), uses just 1/2 to 1 litre of oil between 6k changes (bear in mind it's a turbo), does 32 mpg easily and the engine is clean as a whistle inside (I have photos to prove).
So, which oil you gonna chose?????
PS - I have Torco Fully Synthetic Manual Transmission Fluid (MTF) in the gearbox and Red Line Fully Synthetic ATF in the power steering.
Halfords High Performance Anti Freeze. Mixed at 25% with deionised (not tap) water (good to -14C or so) and 2/3 of a bottle of Red Line Water Wetter.
System flushed every 2 years with plain water till clear. Run for 1 day with water and Holts Speedflush. Thoroughly flush with plain water, drain and refill with above mixture.
Halfords HP antifreeze is one of the new generation long life products and is supposed to be good for 4 years. Comma also do a similar product which is supposed to be very good.
One of the American companies (Torco I think) do a fully synthetic long life antifreeze, but I've been unable to find it here.
I know I'm probably a bit fanatical (and so was the previous owner, a family friend), but the Rover is the best car I've ever had and I got it at an excellent price so I intend to get the best possible life out of it (Garrett only rate turbos with a 100,000 mile life!!). Although I use expensive products I do all my own servicing and maintenance, so overall it costs a lot less than paying a garage (and anyway I have an inherant distrust of garages).
A friend of mine uses Mobil 1 in his historic Formula 3 racer and changes it every other outing (race or practice). The engine has still been in good fettle at each end-of-season rebuild - other people he races rebuild more frequently. Proof of the pudding?
Thanks, I wasn't expecting such a full answer. I looked up the Water Wetter and the price is no joke! I see that it contains a corrosion inhibitor, which I presume allows you to use an anti-freeze solution which seems slightly on the weak side.
Now I'm wondering what your opinion is of petrol additives / fuel system cleaners?
Water wetter can be used with water only (ie no antifreeze) to give best cooling performance. This enables its use in racing cars and hence the corrosion inhibitors.
In a road car in everyday use some antifreeze is required for the winter season, at a mix that prevents freezing according to local climate. Hence I only use 25%. The more glycol there is in the coolant the poorer its heat transfer properties get.
Over the years I've tried a few of the petrol additives. When we bought my wifes Metro it was 6yrs old with only 5600 miles. It was like new except the engine and exhaust were coked up. The exhaust was fixed by having a new one fitted, but the only thing that shifted substantial amounts of the coke out of the engine was Slick 50 Engine Treatment. Its about £12 for a tanks treatment, but was well worth it as the cars economy lept from 35 to 45 mpg after about 200 miles. I tried Redex in my Rover but just ended up gumming up the MAP sensor and it did nothing for the engine at all.
I've heard that 10K Boost is supposed to be very good but at my local factors it's £25 for a treatment. I cannot bring myself to buy it at that price - my cars are simply not that bad!