General Oils - Data

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Oils recomendations California Dreamin This has got to be one of the most frequently talked about topics on the forum and one that has many divided. You would assume that in an area where there have been massive leaps forwards in tecnology that the best oils would be 'the newest' as in: fully synthetic all singing and dancing but that couldn't be further from the truth.

Due to the age/design and generous tollerances in their manufacture our old engines would not benefit in the slightest from these new types and viscosities, infact it has been proven time after time that these oils can have a detremental effect to our particular engine types (use the discussion board if you would like to ellaborate on this)

As the oil requirements vary between engine types lets start with the Air Cooled Petrol engines First

Contrary to URBAN MYTH monograde oils are not the best for aircooled variants:

First choice should be a good quality 15W40 Mineral oil. 15W50 is also a good choice (Duckhams Hypergrade is one product that springs to mind) It is also accepted that the older Mineral 20W50 grade works well (personally I would use the first on this list)

Water Cooled Flat 4 engines

It is almost universally accepted amongst enthusiasts that a good quality 15W40 Mineral oil is best for this engine type. Using a 'thinner' oil (10W40 for example) will result in 'noisey tappet' syndrome, where the thinner oil drains from the hydraulic tappets and the engine starts and runs very noisy for the first 15 minutes (doesn't do anything for camper kudos lol)

Diesel Engined variants 1.6/1.6TD/1.7 & 1.9 modified

This is another TOPIC FOR DEBATE as almost all 'normal' engine oils state on their labeling quote: (ALSO SUITABLE FOR DIESEL AND TURBO DIESEL ENGINES) whilst these oils will do little harm in the short term the WIKI is about recommending the most ideal products.

Let me show you a quote directly from the MILLERS website

Do I need different oil for a diesel and petrol engine?

Generally the answer is yes for older vehicles, as diesel engine oils have higher detergency levels very simply put!

These are a few extracts from various articles explaining the differences in requirements of Diesel Engines:

Very simply the three main areas are: Higher dispersancy to deal with higher levels of soot Higher detergency levels to minimise depositing on components and as a result a higher TBN which will minimise the risk of Sulphuric Acid formation from diesel dilution. Another quote: Yet another crucial difference between petrol and diesel engine oils is that diesel engine oil has more additives per volume. The most prevalent are overbase detergent additives. This additive has numerous roles, but the main ones are to neutralize acids and clean. Diesel engines generate a great deal more soot and combustion byproducts. Through blow-by, these find their way into the crankcase, forcing the oil to cope with them.

Diesel oil recommendations

Look for a Diesel oil specific (an oil primarily for Diesel Engine Use) A good quality 15W40 would be the best choice here.

I have purposely left out the arguments/reasons and discussions behind these choices, feel free to add your opinions in the discussion area.

Mineral Vs Synthetic (Some comparisons)

For purposes of comparison, we have taken a well-known synthetic engine oil, Amsoil 10W-40 synthetic, and contrasted its characteristics with those of several prominent 10W-40 conventional motor oils. Below is a condensed summary of the results of several closely-monitored field and laboratory tests:

Mineral Vs Synthetic tests
Test Amsoil Synthetic 10W40 10W40 Petroleum based oil
Effective lubrication range -60 to +400 F 0 to +300F
Visc. incr. after 64 hr. test 9% 102 to 400%
Wear (mg. wt. loss, Falex test) 1.1mg 3 to 6 mg
Fluidity @ -40F flows freely solid
Volatility (evap. @ 300F for 22 hrs) 1% 28%
Crankcase Temp.(Track Test 240F 290F
Flash Point (D92 test) 470F 400F
Oil consumption (50k miles) 42% less than petroleum oils ~
Intake valve deposits (50k miles) 32.1 grams 75.5 grams