Engine Oil Info

jumper918

Member
Have seen a tonne of people asking (or wondering like myself) about engine oil and the such. There didn't appear to be any dedicated post for that info and Stoney posted up a great blurb in the mini-chat so figured I'd pass this along for the future.

If anyone else wants to chime in with some info such as brand specifics etc. let me know and I'll add it below.

Any info contained here is a general guide only. Please consult an expert before changing or doing anything with your engine. No responsibility taken by myself, AL, or any people whose info is contained within.

Below info was originally by Stoney all credit to him - slightly edited for spelling/grammar.

"Most mechanics will put 15w40 in almost every car that comes through their workshop as it was at one stage the most universal oil for most cars. However today there are so many requirements on oil, that you cannot do that anymore without knowing more information.

If the manual recommends a certain oil, then its a good guide but not always accurate especially when it comes to age and wear. In some cases a thinner oil is needed if the engine has been neglected, and has oil flow issues and a full teardown isn't feasible. The theory all the grey nomads use of thicker is better for old engines (i.e. more than 200,000) is also a very invalid and if not damaging theory.

Thicker may work for worn rings but thats about all, and even then people think its all related to oil leaks but it majorly effects oil pressure and that is more harmful on your engine than an oil leak which should just get fixed anyway. People should stop being lazy lol.

You also have to pay attention to the specs of the oil. There are at least 5 different 15w40 oils available at any given time at any auto parts store that carries more than 1 brand.

For example you could say use a Penrite 10w40 and a Liquimoly 10w40 and get very different results in the engine on both fuel consumption, wear, smoke, burnoff etc...

In my experience with the lancers and the mirage having both 4g15 and 4g93 SOHC, I tried about 10 different oils between them and found 1 or 2 that work really well and I can tell you neither is a 15w40.

One of the key things to remember next time someone says thicker will solve your issues, remember the oil galleries and jets etc don't change in size with wear, so thickening the oil that is flowing through will not flow as good in an engine designed for thin oil.

There is a lot more to oil also which nobody seems to think about or even know... such as the oil is designed to absorb and dissipate heat to cool the engine and its moving parts which is another way it prevents wear and promotes good health and life in the engine. If you change the oil to another type or thickness that is not capable of doing this as efficient then you are harming the engine.

Does anyone even know what the numbers on the oil mean? Like what does 15w40 mean? What does SL mean? What does A3/B4 mean? What about 502.00 as a random one?

With no disrespect intended for anyone on here, as I don't know many people so therefore cannot have an opinion, but apart from the few people who built their cars and forged engines etc whom I would hope know what they are doing and aren't garage monkies, does anyone know much about what they are doing when they service their car apart from, its a 14mm spanner or yeah the oil goes in the top, or my dad said this is the best just cause!

[Also as to whether the car will feel...] like a boosted engine on thinner oil... that has about as much validity as being told you will fall pregnant by swallowing.

The best oils I found for the g93 was total 10w40 semi-synthetic. It exceeds SN ratings and has a higher quality friction modifier in it that doesn't break down from being used/heated/cooled. So you will end up not needing to top up as often if at all. And fuel economy went up also. This was in a 98 Mr with 280k and possible stem seal in 1 chamber.

I tried it in the g15 too with no great benefit over the Motul turbo light aka h-tech 100 plus (from semi synthetic to 100%).

Both were about even. I had tried thicker oils and found the Penrite range to be pretty much useless in its entirety, Liqui Moly was about the only other one that worked as well in either engine. Being the 10w40 semi in particular but it was mainly good for long open road driving. Around town it seemed to break down too fast to the point of 2l over 2 months. Fyi penrite 15w60 as they recommend was filling up 1l a week and had terrible economy.

Also [if you don't know what] semi synthetic, full synthetic and 100% mean [and]... what group 3, group 4, group 4/5 hybrid are, [it] might be something to research if you're interested in getting the best for your car.

However one small problem remains - no matter how much research you do on the oil, you need to know how each type will work and what impact they will have on your engine in your circumstances. Most people will simply read that 100% is better and therefore should work better, [that is] not the case.

For example should you in and spend $150 on 5l of Motul 300v thinking it's the best, you will have an awesome time around the track for a few hours but if you plan on using it for a daily drive you will have a very good oil, for short time as it will break down too fast and need changing [too] often.

Plus you won't receive it's full potential till you're pushing a lot of boost and red line driving around a track. It will perform like any other oil under normal circumstances just without the life.

If you're not interested [in researching], then the best anyone can do is learn from others who have been there, done that and go off their recommendations.

I should really stop talking lol but you get my point, research will help a lot, then you will reach the point of real world testing being essential."
 
Good boy! Nice thread idea. Almost worth a sticky somewhere

Also, this is straight out of the bible if anyone needs some visual help with understanding some oil

 
Back
Top