15W 40 Oil When Its Recommended 10w 40

[dannyboy2005]

I checked my oil on my cunto before work this morning as i had a hunch i would break down on the M25. Checked the dip stick (While it was a cold engine) and i had a lot less then the 'Min' amount. There was a splash left
:panic::panic::panic::panic:

I had no 10W 40 in my boot (As whatrs recomended) so had to use 15W 40 oil.

I know it will be ok, but what would the difference between 10 and 15 make? Iirc, there the thickness of the oil when its cold? Surely you would like thicker oil rather then thinner oil when its cold, that way its more likely to sit in the bearings and around the pistons and not slide off as its not so thin?

[Chico999]

Pretty sure the 10-15 Is the temperature in Winter?

And the 40 is the viscosity

[adamskiTNR]

Depends on the age and condition of the car.
Thicker oil will be helpful to a worn engine.
But if you have a high tolerance engine like honda engine for example then thinner oil will lower friction between parts. and wont block oilways as easily and can flow faster.

[adamskiTNR]

The numbers are cold and hot grades.
So the W number is the cold grade and the other number is the hot grade. A low cold grade will help in the cold. And the hot grade is the limit of thinning. So a 40 grade oil will not get any thinner than a 40 rated single grade oil when hot.

[Wizzy]

Its multi-grade oil, in the past it was labled as 15w-40s.

W means winter and S is for summer. It basically shows the oils viscosity over two ambient temperature ranges.

[dannyboy2005]

Thanks guys

Its a Punto Mk1. Done about 80K. Dose 140 miles a day motorway driving at a steady 4,000 RPM. Gets used daily.

Ideal the 15W would be a bit more suitable as the engine will be getting used regularly and on a long journey, thus introducing more wear and tear? Esp stuck in traffic and stop start etc.

Halfords recommend 10W-40 But ideally would you guys reccomend 15W-40 for my sort of driving?

(Cars due for a service in the next week or so, going to do it my self)

Thanks