Oil & Cold Starts - Good Advice from Opie Oils

[oilman]

At this time of year, it’s beneficial to use an oil that has good cold start flow properties as it will get to the parts of the engine that need it far more quickly when you turn the key on those sub zero mornings.

The "w" number which means winter is the key here and the lower it is the better cold start performance the oil will have.

A 15w or 20w rated oil will struggle to get around the engine in very cold temps and we would strongly recommend using a 10w, 5w or 0w for better cold start performance.

It is a fact that around 90% of all engine wear occurs on cold start because the oil is at its thickest. The colder it gets the thicker the oil becomes and this affects the rate of flow which affects the rate of wear.

These numbers help to explain the oils thickness and therefore cold flow performance at various temperatures.

Grade.................At 0C.................At 10C..............At 100C

0W/20.............328.6cSt...............180.8cSt............9cSt

5W/40.............811.4cSt...............421.4cSt............14cSt

10W/50............1039cSt...............538.9cSt............18cSt

15W/50.............1376cSt..............674.7cSt............18cSt

20W/50.............2305cSt...............1015cSt............18cSt

Centistokes (cst) is the measure of a fluid's resistance to flow (viscosity). It is calculated in terms of the time required for a standard quantity of fluid at a certain temperature to flow through a standard orifice. The higher the value, the thicker the oil.

Winters in the UK are fortunately not too cold but, below zero temperatures are regular features in some parts of the country.

Compare the thickness of the oil at 0degC and 100degC and you will see the big difference.

Just something to consider on those frosty mornings.

The Opieoils Team.

 

[Ali]

We run 15w50 in the racecars, (summer, sustained high temps/revs) going on the data above, that suggests we're doing it all wrong? Never had any issues?! I also run 15w50 in my road car. Never had an issue.

 

[maupineda]

Got confused, as per the numbers above, the cst values are higher at low temps? 0w/20 seems attractive but isn't too thin for the sports?

 

[Jonny1*2]

We run 15w50 in the racecars, (summer, sustained high temps/revs) going on the data above, that suggests we're doing it all wrong? Never had any issues?! I also run 15w50 in my road car. Never had an issue.

You do live in the warm part of the Isles though

Good info Oilman :approve:

 

[oilman]

We run 15w50 in the racecars, (summer, sustained high temps/revs) going on the data above, that suggests we're doing it all wrong? Never had any issues?! I also run 15w50 in my road car. Never had an issue.

Any idea what oil temps you are getting? Anything under 130C and I'd stick with a good 5w-40 or 10w-40 (I guess you are talking about a Clio track car). Same for the road car (again, if it's a Clio), but I'd go for a 5w-40 for road use to get better cold start protection than a 10w-40. Using a thicker oil is generally not something that causes problems quickly but over time the additional wear adds up. Also, by using a slightly thinner oil, you can get a slight power gain. One of our sponsored drivers was in a Mini race series, all cars had to be standard, so he used a 0w-20 (but top quality, same stuff some F1 cars have used) to squeeze a few extra bhp out. Fuchs/Silkolene did a test on some Suzuki bikes a while back and found that there was a gain of roughly 6% in using a 0w-20 rather than a 15w-50, that's quite a bonus on track. Admittedly, there will be slightly more wear with a 0w-20 and probably more oil consumption, but it can be worth it for those extra few bhp.

 

[oilman]

You could use it, but it's a little thin, 5w-40 or 5w-30 is a better choice.

 

[lindleyp]

useful info thanks but what about gearbox oil, im currently using titan fuchs race syn 5, 75w-90 and on cold mornings changing gear the oil feels more like syrup?

 

[oilman]

It's a bit thick for a Clio, go for a 75w-80 or 70w-80 like the Fuchs Sintofluid, Redline MTL or Amsoil MTF

http://www.opieoils.co.uk/c-670-75w-80-75w-85-mtfs.aspx

Cheers

Tim

 

[Fred@BTM]

OE box oil spec is 75W80

basically in simple terms, in winter, engine oil wise 0W40 is better than 10W40

 

[Ali]

Any idea what oil temps you are getting? Anything under 130C and I'd stick with a good 5w-40 or 10w-40 (I guess you are talking about a Clio track car). Same for the road car (again, if it's a Clio), but I'd go for a 5w-40 for road use to get better cold start protection than a 10w-40. Using a thicker oil is generally not something that causes problems quickly but over time the additional wear adds up. Also, by using a slightly thinner oil, you can get a slight power gain. One of our sponsored drivers was in a Mini race series, all cars had to be standard, so he used a 0w-20 (but top quality, same stuff some F1 cars have used) to squeeze a few extra bhp out. Fuchs/Silkolene did a test on some Suzuki bikes a while back and found that there was a gain of roughly 6% in using a 0w-20 rather than a 15w-50, that's quite a bonus on track. Admittedly, there will be slightly more wear with a 0w-20 and probably more oil consumption, but it can be worth it for those extra few bhp.

Caterham. And miles under 130deg! barely over 100 iirc! And i use mobil1 in the V6.

 

[oilman]

As the temps are only around 100C, use a good 5w-40.

http://www.opieoils.co.uk/c-656-5w-40.aspx

Cheers

Tim

 

[Kam.]

Any idea what oil temps you are getting? Anything under 130C and I'd stick with a good 5w-40 or 10w-40 (I guess you are talking about a Clio track car). Same for the road car (again, if it's a Clio), but I'd go for a 5w-40 for road use to get better cold start protection than a 10w-40. Using a thicker oil is generally not something that causes problems quickly but over time the additional wear adds up. Also, by using a slightly thinner oil, you can get a slight power gain. One of our sponsored drivers was in a Mini race series, all cars had to be standard, so he used a 0w-20 (but top quality, same stuff some F1 cars have used) to squeeze a few extra bhp out. Fuchs/Silkolene did a test on some Suzuki bikes a while back and found that there was a gain of roughly 6% in using a 0w-20 rather than a 15w-50, that's quite a bonus on track. Admittedly, there will be slightly more wear with a 0w-20 and probably more oil consumption, but it can be worth it for those extra few bhp.

Interesting stuff! I think i'll try that on my racecar What temp should I keep a 0w20 oil under? Its going to be more sensitive at high temps obviously though as I run a dry sump system its easier to cool...

 

[lindleyp]

is it 3.1 litres to fill cup box ? (fill to you spill)

 

[oilman]

Interesting stuff! I think i'll try that on my racecar What temp should I keep a 0w20 oil under? Its going to be more sensitive at high temps obviously though as I run a dry sump system its easier to cool...

0w-20 can take fairly high temps, as they tend to have very little additives/polymors in them. The trouble be being able to maintain enough pressure, it is easier on a drysump system, if your oil pump can handle it then try it out.

Cheers

Guy