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Lucas 5w 30 fully synthetic oil?
rich201283 - 13/2/18 at 06:08 PM

Has anyone used Lucas 5w 30 fully synthetic oil?, Ive bought some for my e220cdi, what's people's thoughts on it, is it any good?


Nickp - 13/2/18 at 07:54 PM

Lucas is good oil, I've used it in the past with no issues.
What I would ask though is, what mileage is the Merc? 5w30 is a very thin oil aimed for maximum economy. This is fine in a nice new engine but not so good once it gets up in the miles. I had a Ford Rangers bottom go at 200k. It had FSH but was still getting 5w30 by the dealership at that mileage. I can't be sure that the 5w30 was to blame but I'm sure it didn't help.


rich201283 - 13/2/18 at 08:32 PM

The original oil that mercedes put in is 0w40 - most people put in the 5w40. The car has done 120000.
There's not much on the internet about the Lucas oil


Nickp - 14/2/18 at 07:12 AM

quote:
Originally posted by rich201283
The original oil that mercedes put in is 0w40 - most people put in the 5w40. The car has done 120000.
There's not much on the internet about the Lucas oil


So why put 5w30 in then? That oil is going to be thicker when cold and thinner when hot than what Mercedes specify, which is exactly the opposite of what you want.


Nickp - 14/2/18 at 07:13 AM

quote:
Originally posted by Nickp
quote:
Originally posted by rich201283
The original oil that mercedes put in is 0w40 - most people put in the 5w40. The car has done 120000.
There's not much on the internet about the Lucas oil


So why put 5w30 in then? That oil is going to be thicker when cold and thinner when hot than the viscosity Mercedes specify, which is exactly the opposite of what you want.


nick205 - 14/2/18 at 09:56 AM

Can't comment on the car or oil itself, but from servicing VAG cars they all have a VW specification for the oil - e.g. 504.00, 507.00 etc.

Some specs are for shorter mileage changes and some for longer mileage.

Surely Mercedes have a similar specification system for their oils? Personally I'd stick with that.

I always have with VAG cars and never suffered any the worse for it.


Mr Whippy - 14/2/18 at 01:31 PM

quote:
Originally posted by Mr Whippy
quote:
Originally posted by Nickp
quote:
Originally posted by rich201283
The original oil that mercedes put in is 0w40 - most people put in the 5w40. The car has done 120000.
There's not much on the internet about the Lucas oil


So why put 5w30 in then? That oil is going to be thicker when cold and thinner when hot than what Mercedes specify, which is exactly the opposite of what you want.


If you look at most oil recommendations in the cars handbooks they actually cover many different grades, the most important being the ambient temperature. Mercedes are no different as shown below -



The super thin oils like 0's & 5's only really come into their own in very cold weather (when was the last time it got as low as -25 degs here??) where you'd find quite a bit more power when the engine is cold. In the summer their a bit of a waste of time as even a 20/40 will do. My Volvo is a high mileage one and was on 5/30 but sounded like a bag of nails when cold so switched to 20/40 and it was much happier, the only downside is a small but noticeable drop in power when cold in the winter but a much quieter engine (probably the valve train).

you certainly aren't going to break it using the oil you have (unless it about 25 degs outside) but at your mileage I'd personally stick to a 20/40 grade and take it easy in the winter till its warmed up.

[Edited on 14/2/18 by Mr Whippy]


SuperV8 - 15/2/18 at 04:04 PM

If the Merc spec is 0w40 stick with that.

The first number is all about cold start flow. The lower the number the better the oil with flow and quicker it will protect your engine.

It is the second number that could be 'too thin' not the first.


Mr Whippy - 16/2/18 at 07:27 AM

quote:
Originally posted by SuperV8
If the Merc spec is 0w40 stick with that.

The first number is all about cold start flow. The lower the number the better the oil with flow and quicker it will protect your engine.

It is the second number that could be 'too thin' not the first.


When your engines cold the clearances are larger until the parts heat up and expand so very thin oil in an old engine where original clearances have expanded due to wear can make it noisy until it heats up. This is why you have things like valve clearances etc that all but vanish once then engine is up to full normal operating temp.

A classic example of this would be my landys gearbox which when cold roars away but when warm is quiet, it's not the oil doing a better job as it's getting thinner but just the worn bearings expanding and taking up all that wear...

[Edited on 16/2/18 by Mr Whippy]


SuperV8 - 16/2/18 at 03:49 PM

Taken from Opie Oils.co.uk:

Oil Viscosity / Grade

Viscosity is the most misunderstood aspect of oil and yet it is the most important.

Viscosity is the force required to shear (break) the oil at a certain speed and temperature. Oils work because they have viscosity; the drag of a rotating part pulls oil from a low-pressure area into a high pressure area and “floats” the surfaces apart. This is called “hydrodynamic lubrication” and crank bearings depend on it.

Oil must be capable of flowing at low temperatures, so that it gets around the engine in a fraction of a second at start-up and must protect engine components at high temperatures without evaporating or carbonising and maintain adequate oil pressure.

The numbers on every can of oil indicate its performance characteristics when new but there are many misconceptions on what these numbers actually mean

For multigrade oils you will see two numbers (for monograde oils only one). The first is followed by a “w” and is commonly 0, 5, 10, 15 or 20. The second number is always higher than the first and is commonly 20, 30, 40, 50 or 60. The first and second numbers ARE NOT related

The “w” number (0, 5, 10, 15 or 20)

When multigrade oils first appeared, a low temperature test called “w” (meaning “winter” not weight) was introduced

Using a “Cold Crank Simulator, the test measures the oils ability to flow at low temperatures.

ALL oils are THICKER at low temperatures than at high temperatures but the lower the “w” number, the quicker the oil will flow at low temperatures

The second number (20, 30, 40, 50 or 60)

This number is known as the SAE (Society of Automotive Engineers) number and is measured in “Centistokes” (cst) at 100oC

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

An oils cst at 100oC determines it’s SAE rating within the following parameters.

SAE 20 = 5.6 to less than 9.3cst
SAE 30 = 9.3 to less than 12.5cst
SAE 40 = 12.5 to less than 16.3cst
SAE 50 = 16.3 to less than 21.9cst
SAE 60 = 21.9 to less than 26.0cst
a decent oil always falls in the middle of the spec so an SAE 40 will be around 14cst.

ALL oils labelled 40 must fall within the SAE parameters at 100oC so everything from a monograde 40 to multigrade 0w-40, 5w-40, 10w-40, 15w-40 are the same thickness at 100degC

Summary

Cold Start

A 5w-40 will flow better than a 10w-40.
A 10w-50 will flow better than a 15w-50
A 5w-40 is the same as a 5w-30
At operating temperatures

A 10w-50 is thicker than a 10w-40.
A 15w-50 is thicker than a 5w-40
A 0w-40 is the same as a 10w-40
Multigrades offer flexibility but manufacturers recommended viscosities should be observed unless modifications have been made that affect engine temperatures or the car is being used off road.