What oil for 6A12 MIVEC?

spetz · Post by **spetz** » Wed Jun 22, 2005 1:20 am

There is so much info about what oil grades etc that it has just made me more confused.

I currently use 5w 50 from mobil 1 fully synthetic. Basically because I believe Mobil 1 fully synthetic oil is the best oil and 2nd because 5w 50 is the cheapest one of the range.
I've been using this since my 1.8 4G93 days and recently started thinking... if VTEC YO!!!!! Honda's need some weird oil (10w 30 or something) does this mean my MIVEC does too?

So which one to use?
I live in ACT, and at the moment it gets fairly chilly here. 10ish degrees during the day, 0 or less at night time.

What should I use????

EURO · Post by **EURO** » Wed Jun 22, 2005 11:04 am

hey spetz,

I had similar problems and heard many many different opinions from workshops... here is what I concluded through that advice. I covered this a few weeks ago in the help section.

the first figure 5 - means the viscosity of the oil at starting temperature. THe lower the figure, the thinner the oil is. (so 0 is thinner then, 5, 10, 15, 20 etc)

W = winter; applicable for winter use.

the second figure, e.g. 30 is the viscocity of the oil at running temperature (once the engine is warm). so a 30 oil would be thinner then a 40 and a 40 thinner then a 50.

Because the FTO engine is a free reving engine and because most engine damage happens at cold start I was sugggested to use 5w-30. Porsche etc use 0w-40 or 5w-40. Castrol or mobile 1 seem to be the most popular.

An oil like 15w-50 etc is normally used to protect against engine wear, and older cars. i have heard a lot of different opinions on when to use this. one mecahnic told me this was a better all round oil and would protect my engine against wear and tear, someone else said the damage was done at cold start and a thicker oil would jsut put more pressure on my seals etc.... so it depends who you ask. The one who recommened 5w-30 said he only EVER uses this grade of oil.

Ford/holden etc all recommend 5w-30 in their manuals from 99 or something onwards.

I have also been told the first figure being lower (e.g. 5 vs 15) will protect more against cold winter mornings, and the second figure being higher (50 vs 30) will protect more against hot/humid weather....

you could therefore go for a 5w - 40 or something, which is thin on cold starts, still reasonably thin once the engine is running at operating temperature but still protects it against hotter weather... it depends a little where you live...

I hope that is correct information, and makes sense to people reading it.. correct me if i am wrong

spetz I wouldnt choose an oil the price being lower .. one thing that I am clear on is that oil quality and changing is one of the biggest factors in engine life. So I would always pay a bit more if it meant getting a better oil for my car.

spetz · Post by **spetz** » Wed Jun 22, 2005 5:08 pm

So how is 5W-50 then for winter?
Or should I go for 0W-40?

I do oil changes every 4000km.

Also I always warm up the car before driving and always take it easy until oil temps are up. I also have an oil temp gauge

What is the best time to rev an engine? I heard oil temps around 80-90 is best?

EURO · Post by **EURO** » Wed Jun 22, 2005 5:27 pm

4000km oil changes is very frequent - a good thing.

As I have said, it becomes an individual choice. The manual says 5w -30 so, thats what I will use from now on, but having said that a 5w- 50 should also be fine. 5w will cover you in as cold conditiions as you are going to face.. it just means the viscocity of your oil is a little bit thicker once the car is at operating temperature.

I dont know the answer to your last question. I have heard steve (ithink) say you should let your engine warm up for abotu 10-15minutes before revving it hard.

FTO338 · Post by **FTO338** » Wed Jun 22, 2005 5:35 pm

On a turbo car, a frequent oil change is a good thing, as the oil have to work much harder to protect your engine. But on a N/A, its not a good idea, as the oil need to work through your engine.

EURO · Post by **EURO** » Wed Jun 22, 2005 5:42 pm

whats frequent Kev? I was told 10 000kms it should always be changed, but I know some people suggest 5000 (on NA cars).

FTO338 · Post by **FTO338** » Wed Jun 22, 2005 6:01 pm

On turbo should be around 5000km & N/A 8000km-10000km. People got to remember you need to let the oil work through your engine, or its not doing its job.

Is like putting oil on to a frying pan, trying to fry the food, but the oil is still cold.

BuCkEt · Post by **BuCkEt** » Wed Jun 22, 2005 6:01 pm

Just had my oil changed and am using 5w 40 fully synthetic.

ph3var · Post by **ph3var** » Wed Jun 22, 2005 7:16 pm

Just spoke to RPW about oils when I picked up my car from a service.
5w-35 is to thin for Australian climates and they recommended using 10w-40 fully synthetic minimum or 15w-50 semi synthetic.

EURO · Post by **EURO** » Wed Jun 22, 2005 10:28 pm

ive had people say exactly the same, but others said its nothing to do with climate... its viscocity of the oil that is the issue.

Both SL motorsport and Promech said 15 is far to thick for a free reving engine. They said look at what BMW, porsche, etc use, its all 0w or 5w. The biggest wear taken on the engine is at start up so if the oil is thick it causes excess resistance.

im surpised by RPW considering the holden and ford manual stipulate to use 5w-30 only!! and i dont know any mechanic that suggests using anything but full synthetic!

SG · Post by SG » Thu Jun 23, 2005 12:35 am

The hardest old wives tale for most to overcome is thinking that thicker is better when it comes to oil.

Actually, just the opposite is true. Thicker oil is harder for your engine to move around, which takes more power. This in turn creates more heat, which creates more friction and wear and tear, along with less power and economy. A thinner oil moves through your engine easier and with less energy, providing better overall protection and economy, especially at cold start-up, where more than 50% of all engine wear occurs. Of course, you never want to use too thin of an oil. That would cause excessive wear at high temperatures. Unless your engine was specifically designed for it, and as long as it is in reasonably good mechanical condition, there is no reason to use the heavier oils, such as 20W-50.

Good quality oil, frequent oil changes and a quality oil filter at every change will keep that old hot-rod burnin' rubber for many years to come!

that was from this page: http://www.lincolnsonline.com/article103.html. cant believe i used to think thicker meant better protection

looks like the only negative effect of thin oil is high temperatures