Diesel oil in a 1098 - OK?

Post by **MikeNash** » Tue May 23, 2006 1:02 pm

Greetings comrades!
My manager has just bought herself a VW Touran that still has a couple of year's warranty, a condition of which is to be garage serviced. I've a few gallons of diesel oil left over from the previous Zafira and I see no reason not to use it the Traveller (its standard condition, ie loose but good).
I've been using Halford's red can Basic Mineral Motor Oil 20w/50 API SJ A2B2.
I intend to use their black can Enhanced Mineral Diesel Oil CF4-SJ ACEA B2 E2 and their gold can Part Synethetic Diesel Oil 10w/40 APICF SL ACEA B3A3.
I see no problems but thought I should check with you.
Thanks in advance, MikeN.

Post by **bmcecosse** » Tue May 23, 2006 1:59 pm

It's a top quality oil - however diesel oils contain high content of additives to absorb dirt/gunge etc - it may strip away the gunge that's sealing your pistons to the bores!! It's a slight chance - I would take it !
Did you ever fit that head Mike ?

Post by **rayofleamington** » Tue May 23, 2006 2:03 pm

The halfords stuff with SJ - that's labelled as 'basic' due to marketing, not due to quality and is actually good quality.

IMHO The 10/40 is too thin for an A-series and will reduce your oil pressure when hot. 15/40 is as low as I'd go and even then I'd only do it if I couldn't get a decent 20/50.
Diesel oil should have slightly different characteristics and also different chemical cleaners to a petrol oil, but how much difference it will actuall make in an A-series is beyond my limited knowledge. Certainly if the oil has good ratings it will be better than an oil with poor or non existant ratings.

Post by **Cam** » Tue May 23, 2006 5:32 pm

Yes, I'd agree with Ray. That oil is certainly quality, but I would not use 10W/40 in a 1098 personally. Then there's the detergent issue, so I think I'd give it a miss for the sake of £6.50 for a can of the proper stuff, but it would probably be OK.

Post by **bmcecosse** » Tue May 23, 2006 5:46 pm

10W40 would be ok in winter. I think the original oil was supposed to be straight 30 grade - so 10W40 is better !

Post by **rayofleamington** » Tue May 23, 2006 5:55 pm

10W40 would be ok in winter.

on short journeys maybe, but not when your engine warms up fully.

Post by **bmcecosse** » Tue May 23, 2006 6:04 pm

I was of course thinking of a Scottish winter! Seriously - unless it's getting a hammering - it will be fine. I wouldn't waste the synthetic stuff though - in 2 years time you will need it for the VW.

Post by **MikeNash** » Tue May 23, 2006 6:10 pm

Thanks for your advice, friends!
I'll take a chance and use the diesel oil and see what happens - push back the frontiers of science and all that. Oil pressure with 20w/50 at the slowest idle thats reliable (and a bit lumpy) is about 10/15 psi when the oil's about 75C (measured with a thermometer dropped down the dipstick hole) and about the same with 10/40 grade too. I've got no knock that I can hear when pulling hard, so I'll risk it.

Re the head Bmceccosse, I bought it much as a hedge against my unconverted head failing which has now done 40k miles without additive. I expected it to die long ago. Hope to change it this summer and report on its condition when replacing it with yours.
Thanks to all, MikeN.