supervisor

Hi I no this is a saw point lol but I have a new sti 05 dccd and need to change oil this will be my third scooby and in the past I have always used millers 10/60 but was Thinkin about 10/50 on this one it's only running 350hp at the mow would just like to no what people are using thanks gettin so confused with all different oil that people recommend

chopperman

Fuch 5 w40 titan pro s

supervisor

What about the 10/50

53

iTrader: (41)

Motul 300v 15/50

chopperman

10 w50 is ok but a modern 5 w40 is better in the uk unless your racing. 5 weight will give better cold / short trip protection.

Galifrey

iTrader: (3)

http://www.opieoils.co.uk/p-60235-mi...ngine-oil.aspx

Starts fine in the cold, nothing adds short trip protection other than regular oil changes, as the damage from short trips is caused by not generating enough heat to burn off the water and combustion by-products that form acids when combined.

tubbytommy

iTrader: (20)

5w40

Maz

iTrader: (34)

10w 40 and Millers recommendation here. However now that it is getting warmer (fingers crossed) and if you like to use the power 10w 50 is an option.

https://www.scoobynet.com/subaru-par...l#post10508335

supervisor

I do short journeys to work but do drive very hard when warm 

Maz

iTrader: (34)

I would go for the 10w 40 for road and 10w 50 if you track it.

chocolate_o_brian

iTrader: (22)

This.

when having my car mapped by Bob Rawle recently I mentioned that I do short trips to work (lazyness) and he asked what oil I use. I said 10w50 Millers and he suggested a thinner oil like the Miller 10w40 to help prevent any possible damage from short journeys for the reasons explained above.

So will be using (and sticking to) Millers CFS 10w40 as I'm 'only' running 284bhp on a UK classic.

supervisor

Well surly the 10/50 would give same protection when cold but better when hot and bein thrashed lol

The Pink Ninja

iTrader: (23)

I`ve just bought Fuchs Titan Race Pro S/Silkiline Pro S 10/50, Should be with me tomorrow, Getting ready for the summer

http://www.opieoils.co.uk/p-1145-sil...e-engines.aspx

supervisor

That's what I was Thinkin

chopperman

I was told a modern 5-40 runs cooler than a 10-50

jeffwrx

iTrader: (50)

running millers 10w-50 in my blob sti , might be unrelated to the oil change , but think the car runs better with the 10w-50 than the thinner oil i had before.

TonyBurns

iTrader: (3)

5w40 on both of mine, a 10w50 is good if you track it, for normal driving with some spirited thrown in then the 5w40 will be better, thicker doesnt mean better but neither is too thin.

Tony

Galifrey

iTrader: (3)

Yeah the 10w-50 just becomes superfluous if you do lots of short journeys, hence recommending 10w-40, but if you add in some hard driving sessions or trackdays, then the 10w-50 is worthwhile.

Things to bear in mind with oil are:

the low (w) number means nothing more than its flow rate at winter temperatures, ie it will flow as good as an SAE 10 oil, once warmed up, the low number is irrelevant, and our cars will get to a temperature of 100 degrees quite quickly, often in 2-3 miles.

The higher number is how the oil behaves at higher temperatures (100 degrees iirc but I may be wrong) ie its viscosity at 100 degrees which is a typical engine operating temperature, so at 100 degrees a 50 oil will be more viscous than a 40 oil. Effectively a 50 oil will have more drag and will have an impact on fuel economy in normal use.

If you drive harder on occasion, then the 50 oil will provide more protection than the 40 oil, but this will only be of real benefit if you are sustaining high temperatures for long periods, ie trackdays or racing. But there will definitely be no benefit in using it over a short commute to work only, in fact it could be detrimental in terms of fuel economy.

Oil is changed not when it is "worn out" but when it is contaminated to the point where its protection is compromised. Fuel when burned produces water as well as other products NO2/3 which when the 2 combine produce Nitric Acid. Typically over a longer journey this will burn off (evaporate) and be expelled via the crankcase breathing system. With many short journeys this does not get burnt off and as well as etching engine components, it emulsifies into a nasty mayonaise if left to build up over a long period.

Think about the service indicator in many cars nowadays, this works on the journeys you do in calculating when you should change your oil, ie service the car.

TonyBurns

iTrader: (3)

I'd be seriously impressed if the oil made it to 100 degree's in 2-3 miles, i've seen it take well over 10 miles to get up to a good operating temp (above 75 degree's), even worse in winter, quicker in summer, but still took quite a bit more than 2-3 miles.
Water on the other hand would be up to temp in 2-3 miles

Tony

chocolate_o_brian

iTrader: (22)

Something I learned off here a few years ago and never forgot I don't do trackdays or have prolonged periods of hard driving so the 10w40 would suit me better, Bob did suggest if using Shell Helix, a 5w40, but 10w40 Millers is absolutely fine too. 10w50, 10w60 oils aren't really required for my engine/mods/driving style.

chocolate_o_brian

iTrader: (22)

My understanding is that the water temp gauge (especially in facelift classics) is notoriously inaccurate, i.e. the needle stays at the same point even though the temperature may fluctuate considerably.

Galifrey

iTrader: (3)

Then use 10w-50 Millers CFS and change more often, that will give the extra protection when you drive hard and remove the by products from all the short journeys.

Tony, depends on how long you spend sitting in traffic in that 2-3 miles.

Galifrey

iTrader: (3)

My Classic hits normal operating temp in less than a mile for water somedays, but most cars have a 'damped' water temp gauge, an aftermarket one generally shows much greater swings, depending on the level of damping.