Difference in Oils?

Kleynie

Kleynie

A2OC Donor
Hi all,
Received new engine oil today for my 1.4i, it's type 0W-30, however, I before have been using type 5W-30, it's been fine on the 5W type for ages and that's what I was recommended at the time. So my question, what's the difference? And is it OK to replace my 5W with the 0W?
Thanks,

Adam
 
If you are operating in a very low temp (cold) surroundings, you need a very low viscosity grade, such as 0W30 . 0W30 and 5W30 all have same viscosity at 100 Degree Celsius but at lower temperatures- 0W30 has lower viscosity than 5w30 enables the engine to crank quicker due to being thinner. In the UK there is no real need for 0W30 as 5W30 is more than suitable for our climate. 0w30 is only available as synthetic where 5w30 can be synthetic or blended. All said it "shouldn't" harm your engine and if it has a VW/Audi approval number that is listed for your particular engine then fine.
According to Castrol 0w30 does not have a VW spec number whereas 5w30 does have a VW spec number
 
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My understanding of it is 0 is the lowest viscosity for the coldest environments in order for the oil to flow relatively easy enough in a stone cold engine. even a 10w will flow very well on a cold car in our climate so 5w is perfect in my book and nothing to worry about in our climate. The only thing that worries me about the higher 30 viscosity is it's a very low viscosity number for our climate especially so down in the south where it gets really hot during the summer. Many here will be driving in the summer in stop start congested roads struggling to keep cool with just a 30 viscosity. At high speeds on the motorway and heavy acceleration your putting huge pressures on the oil molecules which will start to sheer and break down quicker on a 30 viscosity.The higher numbers like a 40 or 50 have a much higher resistance to molecule break down. Downside to that will be slightly higher fuel consumption and the mean reason why i think Audi use a thirty to give better fuel economy figures. Downside ti this is oil consumption even on new engines. That's why if your going to use that sort of low viscosity synthetics you really should be using an Ester based oil which is of the highest quality and resistance to sheer forces breaking down the oil molecules. Just my 2 cents worth.
 
The oil in question is Castrol Edge 0W-30 fully synthetic. This is what came up when I put the reg number in Euro Car Part so I just ordered it. It was only when it turned up that I realised I used 5W-30 last time.
Is it ok to mix the two?
 
If the oil is still in the carton I would exchange it for an oil with the correct Audi spec. There should be no issues at ECP, they made the mistake.
If it where allready in my car I would leave it there and enjoy the starting benefits on the one or two realy cold days we get each year.
 
There are some oils with 0w30 and yet the relevant spec (502.00 or so). The viscosity grade does not affect whether the spec is fulfilled or not. Apparently there's also 10W40 with the norm (which will probably help noisy lifters). Apparently 0W will be used faster than 5W.

If you mix, you will end up with the lower spec of the two. I use Helix 5W40.

- Bret
 
I got the same result as you when I put my registration into the ECP website. However, the Castrol site https://www.castrol.com/en_gb/united-kingdom/car-engine-oil.html recommends Castrol Edge 5w-30 LL oil and that is a better option. ECP have the 5w-30 LL version listed on their website and it's up to you whether you want to organise a swap.

I have the opposite problem. My oil is changed by my garage, and after I came off the Long Life servicing cycle they switched me from Quantum Longlife III 5w-30 to Quantum Platinum 5w-40. The car has been significantly less happy since that change of oil to the point where I have considered having an early oil change in order to move back
 
I ran my car for years on Mobil 1 0/40 on an extended service but recently backed off to a semi synthetic 10/40 on a 12 month change. Apart from a slower start there is no difference, the car gets a slightly more frequent oil change and I save money.
 
Our A2s were one of the first Audi models designed to use variable service intervals, and the recommended oil was Castrol SLX LL2 - 0w30 grade.
https://www.a2oc.net/community/index.php?threads/service-period.898/post-11784
This changed to Castrol Edge 5w30 around 2005 when the range of recommended oils was rationalised with the more universal VW 504 / 570.00 specs being introduced.
In general driving, sound reasoning suggests that most engine wear tales place during the first few minutes running, with turbos being particularly vulnerable to lack of oil flow. Ultra low viscosity oils minimise this risk which is why I've gone back to 0w30 grades now the correct VW specs have become available. - https://www.shell.co.uk/motorist/oi...2X3RkaV9jbGhhXzc3a3dfcWcwXzJfYTNfRUZ0OFBrVEdN

There is also a theory that low viscosity formulations don't always result in higher oil consumption. From cold they circulate more quickly to minimise metal to metal contact and minimise wear. The piston rings also have an easier time scraping the oil off the bores rather than riding over a 'thicker' film and allowing oil into the combustion chamber. If bore / ring wear already exists, that's another story
Valve guide bore and seal wear however would allow more oil into the combustion chamber on the overrun on a petrol engine. This does not apply to the same extent on TDIs as there is generally positive pressure (turbo boost) in the intake ports rather than 'vacuum' minimises the amount of oil being drawn down the valve guides

Cheers Spike

PS. just spotted that the odd bottle of Castrol SLX oil is still available on ebay - https://www.ebay.co.uk/itm/Castol-SLX-1-Litre-0W-30-Longtec-oil-BMW-Mercedes-Volvo-VW-/132835931391
 
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So carrying on from what i mentioned earlier in hope some of you will treat your engines to this ester based oil because i think you'll love it.

I've used the Shell Helix synthetic myself for years untill i started seeing the wholesale recommendations on another forum for ester based oil in this form.

Fuchs Titan Race Pro S 5W-30 Ester Synthetic Engine Oil 5 Litres 5w30

Ive put the correct A2 grade up above and below as specified 0w - 30 although i use both of these in a couple other cars in 5w - 40 correct for them.

Millers Oils CFS NanoDrive 0W30 Fully Synthetic NT+ Race Engine Oil (5L)

Just for some realtime testing and not just hearsay, i decided try these special "Ester based oils" i kept on hearing about and how the engine felt silken and smoother with this new oil.

When i bought my 1996 S6 Saloon 3 1/2 years ago now, i decided to do an oil change and use the following oil like a flushing agent at the same time. I used a new can of Shell Helix Synthetic this stuff, Shell Helix Ultra SAE 5W40 Fully Synthetic Car Engine Oil 5L ACEA A3 B4 5 Litre Once i had driven the car a 1000 miles, a couple of months later, i emptied it out and filled with Fuchs Titan Pro S 5w - 40. The difference in the way the engine felt was obvious and well worth the extra £20 odd extra pounds over the cost of shell helix. I've been buying it ever since and recommending it if anyone asks.

Give it a go, you won't regret it i just think some of you would like to know for your pride and joy. :)

I
 
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