Mobil or Castrol

[richarda0109]

As a Merc owner for a number of years I have always used Mobil 1 in the 2 diesel Mercs that we own. Lately whilst working in Manchester I got talking to the local Merc Dealer and they said that they actually recommend "Castrol Edge". What are peoples thoughts on this?

Secondly for diesel engines is there a big difference between 5W30 and 5W40.

Cheers

Regards
Richard

[P.Nott]

Some time ago, I was talking to a University pal of my son, who now works for Castrol. Part of his responsibility is analysing and carrying out wear characteristic tests on competitors products. Being a long time petrolhead and obviously interested in using the best products available for my cars, I was talking to him about this very subject, whilst fully expecting him to recommend Castrol products as being the best.

Interestingly, his considered opinion was that the best, widely available, synthetic oil to use is Mobil 1. He said it outperformed even their own 'Castrol Edge' product by a sufficient margin to persuade him that it is the only oil to use for those who care about their engines longevity. For obvious reasons, he doesn't usually state this opinion in public, but it's a good enough reason for me to always use Mobil 1.

So there you have it, pretty much straight from the horses mouth, as it were.

My own, perhaps rather cynical, view of dealers who recommend an alternative product for use in or on your car, is that they only do so because they receive a rather better discount for it than for others on offer.

Edited by P.Nott on Monday 11th June 11:21

[355spiderguy]

hi there.

i have always supplied the oil to my merc main dealer for servicing and always supplied them with mobil 1.

however, last month when our V8 diesel GL went in for its service, i got the call saying the 5 /40 mobil 1 was not suitable due to problems it may cause with the particulate filter, and if they put it in it would invalidate the warranty... i have a great relationship with my service manager so they matched the price i paid at costco for the mobil 1 and put their 5 / 30 mobil 1 in instead.

last year with my previous V8 diesel GL the 5 /40 mobil 1 i supplied wasn't a problem, and this time they didn't say 'no' to my oil for them to rip me of with their supplied oil, so go figure...

hope this helps. ( a bit! )

[P.Nott]

355spiderguy said:

hi there.

i have always supplied the oil to my merc main dealer for servicing and always supplied them with mobil 1.

however, last month when our V8 diesel GL went in for its service, i got the call saying the 5 /40 mobil 1 was not suitable due to problems it may cause with the particulate filter, and if they put it in it would invalidate the warranty... i have a great relationship with my service manager so they matched the price i paid at costco for the mobil 1 and put their 5 / 30 mobil 1 in instead.

last year with my previous V8 diesel GL the 5 /40 mobil 1 i supplied wasn't a problem, and this time they didn't say 'no' to my oil for them to rip me of with their supplied oil, so go figure...

hope this helps. ( a bit! )

I was also told the 5-40 Mobil 1 wasn't suitable for my current 350 CDi for the same reason, although it was fine in my previous 320 CLK. 5-30 Mobil 1 is, however, fine in the newer car with a DPF.

[r129sl]

I have always been a fan of Mobil 1 but I suspect that for ordinary road use there is no significant difference. Anyway, frequency of oil changes is more important than anything else. If you want to look after your engine, you're better off changing the oil more often than using any particular brand. I try to change the oil and filter every 5,000miles at the most. It is something anyone can do himself and takes no more than half an hour.

[richarda0109]

Thanks for all your replies.

In the end I stayed with the tried and trusted Mobil 1. Was in my local dealership picking up some parts and I decided to ask them how much 5L of 5w30 would be - £87.00 - they are having a laugh.

Anyway yesterday I noticed that Halfords had knocked 20% off their price so bought 2 x 5L Mobil 1 5w30 for £83.50 - result.

Regards
Richard

[yellowbentines]

If you have or can find a friend with a Costco card they usually sell Mobil 1 at very competitive prices.

[r129sl]

Costco used to be £25 for 5L. Presumably it's a bit more now.

[richarda0109]

Thanks again for your replies.

I am a Costco member and thats where I looked first of all. Costco ar doing great deals on Castrol Edge 5w40 (£30 inc vat for 4L) and also Mobil 1 5w40 (£30 inc vat for 5L). They are also doing a stonking deal on Castrol Magnatec - I think 2 x 4L for £40 inc vat

The problem I had was that I had to source 5w30 due to this DPF (Diesel Particulate Filter) hence paying the extra £20 for the Mobil 1 5w30.

Regards
Richard

[220cdi]

Another vote from me for Mobil 1 (and from Costco). I have always used it in my Merc, and took my own to the dealer when they used to service the car for me, to avoid paying their rates for oil.

[CarsOrBikes]

The dpf's require a 229.51 oil I think, and the slightly older Mobil 1 you guys have may only be 229.5 which isn't the low ash a dpf requires

Personally i'd consider using a cheaper correct grade oil and halfing the oil change interval, or more.

The dealers staff say they 'recommend' but that likely isn't the case, they sell what they're told to sell by the head offices based on £ltr and rebates.