engine oil - 5w 30 vs 10w 40

[skyblues11]

Hello All,

Just had a 40k miles full service done over the weekend and after me asking the garage not to use longlife oil, i got given 10w 40.I only realized this after looking at the paperwork last night.

I rang them and the mechanic said it was according to the book. I looked at the manual and there is a table showing VW 502.000 oil standard for Time and distance. Furthermore, there are oil of 10w 40 spec that meets the standard. So in that sense, he was 'right'.

The place that did it ( a VAG specialist) , is too far from home and i only used them because i was in that area over the weekend.

Personally i am not too convinced and now worried about the damage this oil grade might cause over the next 10k miles. Should i get it drain out and put some proper 5w30 back in? If yes, how soon?


This episode also raises an issue - how do we ever know what oil a generic garage put into a customer's engines ?

[Cuprabob]

To be honest. I can't understand why you would tell them not to use longlife oil, even if the car or on T&D service regime. It's of the highest quality being fully synthetic and meeting the more stringent VW505.00/507.00 specs.

A 10W40 that meets VW502.00 will be fine in a petrol car for.T&D service regime and is unlikely to cause any issue at the ambient temperatures in this country.

[skyblues11]

i thought, thru reading and researching, that the 2 regimes has separate oils and that is like red and white wine, i.e. one for one purpose. I read that if you use normal oil as top up on top of Longlife, it will bugger up the Longlife regime. This was why i asked for normal oil as i am following the T&D regime, since a year ago i realized i was doing mainly city driving.

Back to the main point, i am worried that i was given semi - synthetic 10w 40 because after all , the service costed 225 quid, rather than over 300 quoted at my local dealer. If i have it drained out and replaced, National tyres would do it for about 39 quid, so i still would have saved..

Speaking of temperature, its getting cold now and we may get a white x'mas, so i don't know if the 10w 40 is up to the job.

[Cuprabob]

No, it doesn't work like that, longlife is a higher quality oil as it needs to be for the extended intervals. In fact, most VW dealers now use longlife oil irrespective of which service regime a car is on. There is nothing special about longlife oil other than it is fully synthetic and meets the higher 504/507 specs.

Longlife oil can be used for T&D and longlife regimes whereas "normal" oil can just be used for T&D. If you mix them then the lowest common denominator prevails which is change at 10k/12 months.

10w40 is well up for the job, our ambient temperatures don't really get that cold but if it makes you sleep better then I would change it.

[Cuprabob]

By the way you can pick up 4 Litres of Castrol Edge 5w30 for around £30 from Costco or £36 from Asda. Castrol Edge is what the car leaves the factory with.

[skyblues11]

that is the problem with the interpretation of both regimes. I was led to believe that the driving style dictates which oil you should have, rather than just a choice of oil quality.

I am surprised VW uses Castrol as a supplier. i thought they would go for some lesser name like Quantum as the factory supplier. Castrol sounds too 'high street''.

everyday you learn something new. thanks Bob for the advice. i might leave it for now but will bear this in mind when i reach 10k miles. Might even try it myself, i remember RW1 did a write up on how to.

[sadtranz]

personally would prefer 10w 40 for yearly change, less oil leaks when cold and better viscosity when hot

[Cuprabob]

that is the problem with the interpretation of both regimes. I was led to believe that the driving style dictates which oil you should have, rather than just a choice of oil quality.

I am surprised VW uses Castrol as a supplier. i thought they would go for some lesser name like Quantum as the factory supplier. Castrol sounds too 'high street''.

everyday you learn something new. thanks Bob for the advice. i might leave it for now but will bear this in mind when i reach 10k miles. Might even try it myself, i remember RW1 did a write up on how to.

Not sure if it's still the case, but Quantum oil was Castrol rebranded.

Although Castrol is "high street" they work with manufacturers like VAG and BMW on lubricant development.

Oil brands are like tyres, everyone has their opinions and a favourite.

[skyblues11]

Besides the grades, i am worried if it is part synthetic rather than full synthetic.

When my waist size was in the 20s. I worked in an independant garage as part of my work experience and used to fill up cars with oil from a big generic barrel.

Today, i wonder what oil these garages put in cars when they service them. They can't be stocking every grade under the sun.

[Cuprabob]

That's one of tne reason's why VW dealers decided to standardise with 5w30 that meets 504/507 as it's suitable for nearly all the range including diesels with DPFs, irrespective of service regime.

Seriously though, for a standard car doing normal driving semi-synthetic is more than up for the job as long as it's changed before it's 10k miles / 12 months.

The majority of modern cars in this country use.either 5w30 or 10w40. Some specialist cars like BMW M series use.0w60 and older stuff uses 20w50. Each manufacturer do have their own specs but garages don't use as many different grades as you think. Each oil brand tends to make a variant to each manufacturer's specs. If you go to Halfords and read the back of the bottles you will see this.