What Engine Oil to use

Handgunner SG

Does anyone knows whats the meaning of the engine oil indications like 0W40, 20W50 or others... What i know is the density.. Thinner or Thicker.. Got any linlks to recommend to check out Question

kidmccoy SG

for the best cheaper oils best to use the OEM brand oils

personally i dont use that crap they sell at shell... personal preference on my part

for peformance , Montul i heard is the best stuff

as for thickness usually the older the engine the thicker the oil recommended

Gedanken SG

The numbers in the SAE rating (e.g. 20W-40) refer to the viscosity of the oil at low and high temperatures. Think of the numbers as a measure of the oil's thickness, and the first number is the thickness at low temperatures, while the second number is the thickness at high temperatures.

When the engine is cold, you want the oil to be thinner so that it doesn't provide too much resistance as the engine is working its way up to operating temperature. However, when the temperature is high, you want it to be thicker to reduce wear on the engine parts. Viscosity index improvers are added to oils to give them these properties at differing temperatures.

While thinner oils reduce resistance to the pistons as they move in the engine block, the wear also increases. Some estimates are that a 1% improvement in fuel efficiency can result in 30% more wear on the parts.

Also, note that the oil in part helps to seal in the fuel-air mixture as it is compressed and ignited - if it is too thin, compression can be lost. This applies particularly to older and more worn engines, when the space between the piston and cylinder lining is increased, thereby giving the oil a larger gap to fill.

Before choosing what oil to use, it would be best to first check the manufacturer's specifications, because pistons and cylinders are constructed differently in different engines, and therefore require different oils. Also, it is best to perform a compression test on your engine, especially if it is an older engine, to assess its state of wear.

If it's a new engine and in good condition, you might be able to use a 10W-40 oil and get away with it. On the other hand, chucking 10W-40 into an engine that's done 200,000 km will result in you not being able to use your rear-view mirrors because all you'll see is smoke. Mr. Green

Over and above SAE ratings, you will also need to choose between synthetic and mineral oils. Synthetic oils have the advantage of longer life, so you can go further befoore needing to change oil, but it may not be suitable for all engines. Again, check the manufacturer's specs.

hotxyz2002 SG

Which type of engine oil should I use for an old car with an old engine (more than 10 years old). 20W-40? or 15W-40?

Would the use of the wrong type of engine oil cause over-heating of the engine?

Gedanken SG

All things being equal, your best bet is something like 20W-40 or 20W-50.

You might be able to get away with 15W-40, but I've broken a 200,000 km engine that way before - you will need to ensure that the engine is in excellent condition first.

At the same time, don't go all the way to the other end of the scale and chuck 25W-70 in - you will only need that to restore lost compression, otherwise you will be increasing your fuel consumption and losing performance for nothing.

Try 20W-40 or 20W-50 first, and if you find smoke, you can always add an oil fortifier.

Handgunner SG

Wat is the brand of the car....maybe it already got engine problem.... Last time i use 20W50 only on my new Hundai van smoke out like siao... later change to 15W40 better..... But my dad's Nissian double cab over 10 years....still ok using 20W50.....

Gedanken SG

Yup, it was a 1985 Mazda 323 SS - the last owner didn't have a clue about maintenance. When I first took the engine apart, I found that the gaps on the spark plugs ranged from 0.7 to 1.6 mm - he had no idea how to gap a spark plug even. I figured that since I was only going to use it as a student car for a while, I may as well drive it into the ground. Besides, the 1052's engine has a design flaw that results in cracks between the cylinders at 250,000 km - sure enough, the engine went at 250K, and being a $1500 car, it wasn't worth rebuilding (although I did already put extractors on, and was thinking of changing the engine, porting the heads and replacing the Hitachi twin carbs with one 48mm Weber).

Anyway, that doesn't add up - you went to a thinner oil and got less smoke? What colour was the smoke? Did it have a bluish, brownish or white tinge? I suspect the smoke was from a fuel-air mixture that was too rich, rather than burning oil. I'll stick with what I've said - with an older engine that needs more lubrication because of wear, use a thicker oil.

hotxyz2002 SG

I found the following information rather useful:

What's the difference between synthetic and mineral oil?

Synthetic lubricants are made up of molecules that have been modified under complex chemical processes and allow for enhanced performance under extreme conditions of temperature, pressure and forces. Mineral lubricants are composed of molecules present in crude oil that are separated in the distillation process at a refinery.

What is viscosity?

A liquid that has a relatively high resistance to flow can be described as viscous. For example, water has a low viscosity compared with honey, so in this case honey has a higher viscosity than water under the same temperature. A good quality lubricant keeps its viscosity steady under different temperature and usage conditions for a longer period of time.

What is a multigrade oil?

Lubricants that are able to maintain their performance in high and low temperatures are called multigrade. They are defined by two numbers. The first (followed by a W) indicates the lubricants viscosity under lower temperatures. The second and higher number indicates the lubricants viscosity under greater temperatures. A multigrade lubricant minimises viscosity differences under temperature variations.

What are additives and why are they used?

Additives are chemical compounds which, when added to base oils, improve the performance of the lubricants, protecting them from aging and allowing them to respond to all the demands of the modern engine. The blend of various additives is what sets a quality lubricant such as Shell Helix apart from the competition.

My oil consumption is very high. Why?

You would be wise to check for faults, taking into account the type of engine, its age and the driving conditions to which it has been exposed. Faults could be caused by a leak in junctions or seals, wear to pistons or cylinders, or deposits limiting the lubrication of some surfaces.

Does the colour of the oil mean anything?

The colour of an oil has no special meaning, but depends on a number of factors, such as the refining process and the types of base oils, additives and crude oil used. Oil may turn a darker colour after use because it contains a number of suspension particles the reason for this is that oil cleans the engine of particles and other deposits produced by the high temperature combustion, keeping the particles in suspension to avoid depositing them on the engines surface.

What do the classifications and specifications on the back of the pack mean?

Lubricants vary in their use and quality. Some are only suitable for particular engines, while others can only be used in certain weather. Even two oils optimised for the same engine and weather conditions can have vastly different levels of performance. Universal criteria to describe oil performance and usage are therefore used.

The main classifications boards are:

Society of Automotive Engineers (SAE) - defines oil according to its viscosity. Oil can be monograde or multigrade, depending on its viscosity performance at various temperatures.

American Petroleum Institute (API) - classifies oils according to their capacity to protect the engine. The letter S is used for petrol engines and the letter C for diesel. The letter that follows the S or the C indicates the degree of performance and protection, with A the lowest and X highest. Some oils can be used in petrol and diesel engines, so their classification is stated as SJ/CF or CF-4/SJ.

Association des Constructeurs Europeens d'Automobiles (ACEA) - similar to the API, with the difference that while the API is based on American Engines, the ACEA is based on European engines. The ACEA also uses letters to denote classifications.

Extracted from:

http://www.shell.com/home/Framework?siteId=sg-en&FC2=/sg-en/html/iwgen/leftnavs/zzz_lhn4_5_3.html&FC3=/sg-en/tailored/shell_for_motorists/oils_lubricants/helix_rrr/faq_ga_1509.html

kopiosatu SG

Castrol Aerojet 5 is very good!

hotxyz2002 SG

Which type of engine does it work best with? We can't just say that it is good without giving other info.

kopiosatu SG

Turboshaft Engines, Turbomeca Makila

I don't think you should take my posts seriously...

Gedanken SG

Good stuff, hotxyz2002. They just missed out on one thing, though: if your oil is of a milky brown colour, it's time for a very expensive head gasket change! Mr. Green

And kopiosatu, when are we ever going to drive cars at that altitude?

Handgunner SG

I use the 15w40 Mobil Delvac for my Hundai van....still got black smoke(famous for that) but lesser, 2 yr old(but I sold it off now)...ya I also agree use thicker oil with older car. But the front value (W)should be ok right? cos the oil won,t get thinner than 40 I now using Mobil 1 0W40. Now driving a 6yr Civic Sir. Last time use Agrip 10W40 engine quite nosiy, now better liao.... and smoother...

Does anyone has any views pls comment...

hotxyz2002 SG

You are certainly right about the expensive gasket change cause I just had mine changed due to overheating problems and it has already 'burnt holes in all my pockets'!

I was told that the gasket has a lifespan of about 7 years. So for all those would-be second hand car buyers out there, do take this into consideration if you should decide to buy one. And make sure you use the correct oil engine suitable for your engine otherwise you would definitely encounter engine problems.

My advice would be to use 20W-50 (Shell Helix or BP Visco 2000) for older engines because my engine has been working smoothly ever since i use it.

Gedanken SG

If the oil viscosity index is at 10, your engine isn't getting much protection when you first start it up because the oil is too thin. For an engine that's done less than 50,000 km, I would first use a PTFE coating additive, so that until your oil gets warmed up and thicker, you've got a layer of PTFE protecting the moving parts. For older engines, I wouldn't risk using such a thin oil.

Gedanken SG

I've seen gaskets that last up to 17 years. The one big gasket killer is excessive heat, because it warps the gaskets, thereby leaving gaps betweehn the engine block and cylinder head. Because the coolant channels run through the blosk and head, and gaps will also lead to water seeping out, leading to coolant loss and even greater chance of overheating. I make a point to check my radiator fluid levels (plus battery water, brake and power steering fluid and oil) every time I fill up my tank - keep a check on it and your head gasket should last you a very long time.

20W-50 is a very good choice - it provides enough protection at both low and high temperatures. The other thing is never to rev up your engine when it's cold - that will cause a lot of damage to the engine because the oil isn't up to that kind of abuse yet.

I've taken a look at Castrol's Magnatec oil, which is supposed to stay on the moving parts when the engine is off, instead of draining into the sump and leaving the parts dry. I haven't tried it yet, though - has anybody here had experience with it?