|The Oily Page|
T he V-8 engine relies more on oil volume than oil pressure. So the oil doesn't have to have extreme temperature or pressure capabilities. As a result the quality of the oil therefore doesn't need to be of premium quality. So use of synthetic or semi-synthetic oils is not necessary and a bit of a waste of money. If you use your car as an everyday car and plan to keep it with the same engine for a long time, than regular oil replacement will have a better effect on your engine than using the more expensive oils.
A somewhat thicker standard oil doesn't hurt so 15W40 is a good option for use in temperate climates like Holland and the UK. If you already have somewhat worn bearings (indicated by low oil pressure) you better use a thicker 20W50 oil. Make sure though that you use an engine oil with good detergent qualities, particularly for the V-8's as they tend to be very sensitive to oil sludge. Oil as used in turbo-diesel engines has very good detergent qualities so preferably use that.
With synthetic oils like Mobil 1 problems can come up like:
Standard synthetic Mobil 1 is rated at 5/30. If you want to use synthetic anyway (TVR is recommending synthetic in their Rover V8's) then preferably use the thicker Motorsport 4T grade which is rated at 15/40. This will reduce oil consumption and premature wear of the bearings. If you want the oil a bit thinner Mobil 1 and 4T can be mixed.
In the manual it is stated for the older models that oil changes should take place every 5000 miles. For later models it was set at every 12,000 miles, but this figure tends to be somewhat optimistic for the V8. As a rule of thumb an interval of 5000 miles or every year can be used for cars which run short distances. And 7,000 miles or every year for cars which run for longer distances or run on liquid gas. The six cylinders are somewhat less problematic in this respect, however they have a history of clogging oil galleries in the cylinder head which can lead to expensive head rebuilds so change every 7,000 to 10,000 miles or every year.
Also change the oil filter at the same time you are changing oil. Some people only change the filter after every second oil change. Normally it won't hurt but then it's easy to forget it the second time also! and the cost of a filter isn't that big. Another reason is that the amount of flow pumped out by the oil pump reduces when the filter is becoming clogged. The V8 needs copious amounts of oil to keep it well lubricated so it is better not to count beans on this point and just change the filter together with the oil.
If your engine is used for short distances, or you expect a lot of sludge and such inside the engine, you can try the following trick. Before changing the oil. Drain some engine oil (about 1 litre) and top up the oil level with 1 litre of ATF oil (Automatic Transmission Fluid). ATF oil has very good cleaning properties and does a good job of internally cleaning the engine. Leave it about 100 miles in the engine. Then drain all the oil and refill with normal engine oil. It will certainly help a lot.
Most of the wear in an engine happens at start up. Research has indicated that 50 to 75% of your engine's wear happens at start up. When the engine runs an oil film between the engine parts avoids metallic contact and wear. At startup there is no oil pressure and no oil film.
So to reduce engine wear wouldn't it be nice to already have oil pressure and only then start the engine? Well there are systems on the market who can do this trick, and these so called prelube systems seem to work quite well. We will look into this system a bit further.
The system basically consists of:
Now before you start the engine you switch the ignition on and the pump starts to run. You can see the oil pressure rise on the oil pressure gauge. Then you start the engine. The system also switches on after the engine is switched off to enable the hot oil to cool down and carry away excess of engine heat. This is a very important feature if you are using a turbo because the system keeps lubricating the turbo bearings. Remember the turbo still turns at high speed after the engine has been switched off.
So should every body buy one?