endrop - for all your online needs

Oil - Cold weather selection

Currently reading:
Oil - Cold weather selection

oilman

oilman

New member
Joined
Nov 18, 2004
Messages
108
Points
26
In this cold weather, it is 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.

The "w" number which means winter is the key here and the lower the better.

It may seem odd but a 15w or 20w will struggle to get around the engine in very cold temps and I would strongly recommend a 10w or better still a 5w for better cold start performance.

90% of all engine wear occurs on cold start because the oil get thicker the colder it is which causes engine wear.

These numbers explain what I mean and bear in mind that the oil will be the following thickness at 100degC (sae 40 = 14cst, sae 50 = 18cst and sae 60 = 24cst)

At 0degC these are the numbers (thick!)

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

If you are using anything more than a 10w oil, always warm the car properly before driving it as the oil needs time to circulate.

Just a word of warning really.

Cheers
Simon
 
Actually I'd like to add to this.

Use the oils reccommended by Fiat. They take into account the UK weather conditions and the thickness of the oil required to provide mechanical protection at start up and hot running. They designed the engines and they do actually know.

Please don't go changing your oil grades beyond Fiat's reccommendations, if you get it wrong you can cause more damage than you're trying to prevent.
 
Right, have checked this out with a respected engineer.

The manufacturer reccommends a grade of oil to best protect your engine. All aspects of the protection are taken into account - cold and hot starting, hard use, nose-to-tail driving - the full spectrum.

When cold, the oil needs to be a certain thickness (viscosity) for lubrication purposes. When the engine is cold, we all hate the 2 second clatter you can get from the top end until the engine is warm - even Fiat don't want this to happen as it makes their cars sound poor.

Fiat could just say "Oo, I know - we'll drop from a 15w40 to a 0w40 so that it doesn't clatter". But, and this is the point that seems to be missed all the time, there is a reason why the engines need the oil at the reccomended viscosity.

Why?
So the oil is thick enough to keep the metal bits from rubbing against each other. An engine which the manufacturer reccomends a thicker oil for will be at greater risk from damage with a thin oil, as the oil film may not be able to hold the bearing surfaces apart. Inside your engine, the crankshaft and camshaft actually 'float' in the oil - the bearing surfaces aren't actually supposed to grind against each other.

If you put too thin W grade oil in, the engine's oil pressure won't be as it's designed for a cold start, and the oil may not be thick enough to allow the bearings to 'float' - so you get metal to metal contact and advanced wear.
 
fixitagaintomorrow said:
Right, have checked this out with a respected engineer.

The manufacturer reccommends a grade of oil to best protect your engine. All aspects of the protection are taken into account - cold and hot starting, hard use, nose-to-tail driving - the full spectrum.

When cold, the oil needs to be a certain thickness (viscosity) for lubrication purposes. When the engine is cold, we all hate the 2 second clatter you can get from the top end until the engine is warm - even Fiat don't want this to happen as it makes their cars sound poor.

Fiat could just say "Oo, I know - we'll drop from a 15w40 to a 0w40 so that it doesn't clatter". But, and this is the point that seems to be missed all the time, there is a reason why the engines need the oil at the reccomended viscosity.

Why?
So the oil is thick enough to keep the metal bits from rubbing against each other. An engine which the manufacturer reccomends a thicker oil for will be at greater risk from damage with a thin oil, as the oil film may not be able to hold the bearing surfaces apart. Inside your engine, the crankshaft and camshaft actually 'float' in the oil - the bearing surfaces aren't actually supposed to grind against each other.

If you put too thin W grade oil in, the engine's oil pressure won't be as it's designed for a cold start, and the oil may not be thick enough to allow the bearings to 'float' - so you get metal to metal contact and advanced wear.
Click to expand...
:yeahthat:
trust the engineer over an oil salesman any day of the week
 
fixitagaintomorrow said:
Fiat could just say "Oo, I know - we'll drop from a 15w40 to a 0w40 so that it doesn't clatter". But, and this is the point that seems to be missed all the time, there is a reason why the engines need the oil at the reccomended viscosity.
Click to expand...
On turbocharged cars, changing to a thinner oil also means a higher oil consumption, as half of it pours through the turbo oil seals! (May not apply to all non-Coupe cars!)
H
 
OK, I use 0W40 full syn in my Idea 1.9. Fiat reccomends 10W40 summer and 5W40 winter. Both give the same hi temp protection. The 0W40 gives easier winter starting and lower fuel consumption year round. Also, it circulates through the engine faster in the cold, providing more startup protection. My old Clio 1.9D went over 201000 miles in six years on mostly 0W30 compared to the recommended 5W30. If you use regular mineral oil, then follow the maker's advice closely. If the warranty is up, use full syn and double the oil change interval on cars where it must be changed at less than 12000 miles. Extend it by 50% if it's 12000 or more.
 
raton_laveur said:
......... If the warranty is up, use full syn and double the oil change interval on cars where it must be changed at less than 12000 miles. Extend it by 50% if it's 12000 or more.
Click to expand...

Do you mean change at 6000 on a 12000 reccommended interval?

'cos I'm afraid I wouldn't reccommend to anyone that they go to 18,000 if the maker's reccommendations for oil changing is 12,000, or run to 20,000 between changes on a maker's 10,000 interval.

While this may work just fine for someone that does 50,000 motorway miles a year, someone who does short journeys or stop-start motoring can end up damaging their engine if they were to do so.
 
fixitagaintomorrow said:
Do you mean change at 6000 on a 12000 reccommended interval?

'cos I'm afraid I wouldn't reccommend to anyone that they go to 18,000 if the maker's reccommendations for oil changing is 12,000, or run to 20,000 between changes on a maker's 10,000 interval.

While this may work just fine for someone that does 50,000 motorway miles a year, someone who does short journeys or stop-start motoring can end up damaging their engine if they were to do so.
Click to expand...


I'm only talking about with full synthetic oil. It's more expensive on the day you buy it but cheaper ever after because it lasts much longer than conventional oils. Don't be fooled by part-syn or syn blends. They usually have less than 10 per cent syn in the mix. What you can do is continue to change your filter at regular intervals but leave the full syn oil in the engine, just remember to top it up after the filter change. Mobil has tested it's Mobil 1 to beyond 25000 miles without any hint of breakdown. I imagine the other name brand full syns are similar. BTW? I would never use Castrol full syn. It is "Full Synthetic Oil with Nonsynthetic Ingriedients". They are trying to say that it's got some regular oil in their supposed full syn. That's crap. You pay the full syn price but you don't get what you pay for as it costs Castrol a lot less to make this stuff than their former 100% full syn but they never lowered their prices.
 
You must log in or register to reply here.

Similar threads

C
Oil change.
Replies
0
Views
102
CaradoSteve
C
AndyRKett
Need help tracking down an oil
2
Replies
30
Views
1K
bugsymike
B
V
VVT FIRE..oil choices ?
Replies
12
Views
675
chris3234
C
D
Oil light is flashing at start-up for 30 seconds
Replies
0
Views
256
Donegood
D
D
Camshaft oil seal
Replies
2
Views
329
varesecrazy
V
Back
Top