VAG lickers! Don’t buy Halfords 507 5/30w

[Dj_efk]

I’ve always been a “use anything that’s been blended for the correct spec and change it regularly” type of person but my experience with this stuff was so poor on our Touran 2.0TDI 150, it has prompted me to want to warn others:

 

When I put this stuff in at the last oil change, the engine consumed a fair amount of this oil from the off, meaning I needed to top up fairly often. To be honest it does use a bit so I just thought given it had 123k miles on it perhaps it was just ageing. What was really worrying though is that by 7000 miles after the change (having topped up the best part of 1.5 litres), the engine oil temp was getting slightly elevated on the motorway at 65-70mph (reaching 100-106 degrees instead of hovering just below 100). It was then taking longer than usual to cool down again: To me this is indicating the oil is no longer providing the level of protection that it should. I noticed the car was regenerating more than normal too, although I’m not sure if this is related.

 

I’ve just drained it at 8000 miles (my regular interval is 7500-8000) and it was sludgy and pitch black to a level far beyond what I normally see.

 

I’ve now filled it with Quantum III from TPS and the oil turned black almost immediately - after a 20 mile run: Normally the oil would gradually darken over a few thousand miles after a change - so I’m going to change the Quantum again after 2500 - 3000 miles as a flush interval.

 

My conclusion is that whoever blended this oil for Halfords has not done it correctly, hence Halfords own-brand oils are now blacklisted from my vehicles!

 

Appreciate folks tend to have strong opinions about oils but thought some might find this experience interesting to read about

[Brigsy]

The 5/40 is not much better from experience. I used it to flush an engine after top end rebuild, came out like piss after a short run. 

[Bren]

Not like it's particularly cheap either.

[Popsicle]

Interesting and worrying take on the oil spec from Halfords. But TBF diesel oil tends to go black very quickly, but it shouldn't be sludgy, nor should it start suddenly using an excessive amount.

I've only used Mannol 5/30 507 oil in my PD Caddy and CFFB Passat, I keep thinking about using a different brand, mainly due to stories about Mannol oil not being able to meet spec at the price point. However, the two vehicles have a combined 700k+ miles on them, so I'm reluctant to change brands as it seems to be working - touch wood.

[Dj_efk]

Mannol 7715 is that?

The one they used to have VAG approval on?

VLS Investigation: In 2024, the Verification of Lubricant Specifications (VLS) investigated this product, noting a potential discrepancy between the claimed HTHS viscosity (3.5+ mPa·s) and test results (3.13 mPa·s), which did not meet the strict VW 504/507 standard for high-temperature/high-shear. However, it is still widely marketed as approved.

 

PD engines rely on film strength due to the massive loads put on the camshaft bearings - so I would strongly encourage you to consider switching to something that is VAG approved…

[vaughant]

Years ago I used to buy the vag oil to go in anything as it was actually cheaper direct from Sinclair's than from a motor factors. I want to say it was called Syntech but Quantum rings a bell. 

Either way I'm sure it wouldn't be hugely different to a factors. 

VAG seemed to love an oil change years ago and in my experience they always ran a lot better and quieter, as they never made the quietest engines but always a solid motor in the MK1/2 GTi's.

[Popsicle]

9 minutes ago, Dj_efk said:

Mannol 7715 is that?

The one they used to have VAG approval on?

VLS Investigation: In 2024, the Verification of Lubricant Specifications (VLS) investigated this product, noting a potential discrepancy between the claimed HTHS viscosity (3.5+ mPa·s) and test results (3.13 mPa·s), which did not meet the strict VW 504/507 standard for high-temperature/high-shear. However, it is still widely marketed as approved.

 

PD engines rely on film strength due to the massive loads put on the camshaft bearings - so I would strongly encourage you to consider switching to something that is VAG approved…

Yep the 7715 one. I've read similar stuff about it not being in spec any more - other firms have doubted that Mannol can produce the base spec oil and additive pack for the price they retail at.

The camshaft on my Caddy was replaced at 217k miles, injector lobes had worn out.

Thing is, it's been run on Mannol 7715 since, it's now on 493k miles. I'm loath to change as it just works, when the previous camshaft failed I'd had 80k miles of it being difficult to start when hot, it's fine at the mo.

I would hate to change and something let go, even though it might let go without change, I couldn't moan at it with the miles on it.

Decisions, decisions.....

[colino]

Diesel oils should go black pretty quickly after an oil change, it shows the high detergents are working and keeping those nasty sooty particles in suspension.

[Dj_efk]

Yes correct for cars treated to standard drain intervals or thereabouts, but because I change mine earlier than most (oil and a filter are cheap insurance when the labour is free), what I usually see is a gradual darkening golden brown colour until it’s gone black in around 3000 miles - this time it was almost instantaneous!