Wrong oil damage VW tdi engine?

How the hell is that cheap? £25 a gallon?

Jeez, I get 5 litres for a fiver in Asda ! ;-)

asahartz ( snipped-for-privacy@hotMEATPIEmail.com) gurgled happily, sounding much like they were saying :

There's cheap, and there's inexpensive.

If it was the correct VW 505.01 oil it would have been very cheap indeed.

Yeah, oil of such quality I wouldn't use it as chain lubricant.

JB

I find it hard to believe that this oil could make that much difference to the economy. It will not affect the engine in that short time either. The only way an oil can give better economy is with a lower viscosity rating, which most fully synth oils will give. 15/40 sounds like a semi-synth oil. Be interesting to see if the economy improves with the oil change. They might have done something else while servicing.

theres cheap, there's inexpensive & then there's Asda's cooking oil @ a fiver !!!

How does it perform?

The price isn't too cheap- GSF retail a quality PD oil for 5.70/litre, but the grade of the stuff you have is wrong- I *think* all the 505.01 oils are 5w/40 or better, and doubtless the oil doesn't meet 505.01, which is the minimum for PD engines. It's a bit thick, but I wouldn't expect that to knacker the economy, unless the hydraulic tappets are playing up?

I'll bet it wasn't.

Probably not. You'll never know to be sure though. The PD oil has a high shear capacity (due to the unit injectors placing a high load on the cam). To be honest, I'm very wary of using any garage that appears not to know the car well. The PD has been around long enough now for everyone to know about the oil requirements. It's probably even on or near the oil filler too.

reg ( snipped-for-privacy@ihatespam.com) gurgled happily, sounding much like they were saying :

No, that's definitely *cheap*... with particular emphasis on all the (negative) connotations of the word...

It goes alright, it's just thirstier.

35mpg instead of 40 around town, 40 instead of 45 on a long jouney at the weekend. That's a significant drop.

It's a small but well respected local garage. I used them a few times and never had cause to doubt their knowledge or skills but given how long the PD engine has been around, I'm genuinely surprised at this c*ck-up.

Tim

15w/40 is only 'thicker' than 5w40 when its cold, not hot so you wouldn't expect it to hit your long journey mpg at least. I suspect that possibly something else has changed or maybe your old oil had gone really thin. See what happens with your new oil anyway. Even cheap new oil is better than expensive old oil (within the correct viscosity range) especially with turbos. I doubt any damage will have been done.

Remember that even the manufacturers recommend thicker oils for hotter countries (and thinner for colder) for the same engine.

Z

Well, it'll be interesting to see what happens but I've never had such poor fuel consumtion on a long journey.

My car has had a problem recently when cold that I've only just realised has been happening since the oil change. At steady low speed the engine has been running roughly with a bit of "shunting" through the drive train. This has disappeared as the engine has warmed up.

Well, I did get two new front tyres but I made sure that they were well pumped up before my long trip. It's certainly possible that they were a factor but I'm more inclined to blame the oil. We shall see...

Regards

Tim

New tyres will probably have a greater diameter than the old ones, causing the car to think it has travelled less far than it really has on each litre of fuel. This would only account for about a 2% difference though.

Well, the garage changed the oil & filter for VW stuff FOC and the fuel consumption has improved already (back to being on the right side of 40, even around town).

I know there are doubters here who don't believe that oil can make that significant a difference to fuel consumption but I'm convinced.

When I went to collect the car I offered to pay for the oil and filter change *if* they could show me where it said that their 14W/40 oil was compatible with the VW Tdi PD engines. They declined my offer so I still don't know whether it was compatible or not.

Tim

The older spec VW long life oil was 5w/40 fully synthetic. It's the exact same stuff as Vauxhall used to spec for their diesels on vairable service intervals, as the drum we've got at work lists the VW 501 spec on it.

The latest VW long life spec (601.01?), comes in a drum with only that number on it, and even at our majorly discounted bulk prices, is very expensive.