Best oil for a BX diesel.

Mothman · Post by **Mothman** » Thu Mar 03, 2011 9:46 pm

Now that the MOT is sorted, can a forum member recommend the best make of oil for a non turbo diesel?
Going to do the oil and all filters on Saturday.

Andy

Post by **Defender110** » Thu Mar 03, 2011 9:51 pm

Each to their own realy when it comes to oil, Any good quality non synthetic diesel oil will do.

MULLEY · Post by **MULLEY** » Thu Mar 03, 2011 11:53 pm

I must admit to not having a clue as to how to tell the difference between a good oil & a cheap one regardless of whether its mineral, semi or synthetic.

For my TXD i just buy mineral oil & just keep an eye out for the cheapest price i can find. I've bought some from wilkinson's for my next oil change, seeing as it only stays in the engine for 6k, does it matter?

I did use to use semi, but then was warned that mineral oil has certain properties in it that semi doesn't, so infact by using semi it wasn't as good as mineral

I use 15w40 & the engine is coming up for 126k, at what point should i perhaps change to a different viscocity & then which one would be appropriate? or just leave as is?

Apologies for the slight hi-jack, but hopefully any debate off my questions may help you decide what to go for.

Post by **mat_fenwick** » Fri Mar 04, 2011 12:02 am

IMO there should be no need to change from the recommended viscosity to a thicker one, unless the engine is seriously worn. And in that case it's hardly a long term solution to bung some thick oil in it!

I buy on price too, so long as it meets the right specs (look for B3 for a diesel oil, although most seem to also have the petrol A3 equivalent marked on it) then I can't see the problem. It's a lot cheaper in bulk though, I pay about £40 for 25 litres of mineral 15w40.

MULLEY · Post by **MULLEY** » Fri Mar 04, 2011 12:19 am

B3

This is foreign language to me

If it's not that number, what issues can it cause? I presume that this is just the latest technical version of oil for legislation reasons, & therefore anything that preceded this version was suitable at the time & therefore in reality it doesn't matter

Post by **mat_fenwick** » Fri Mar 04, 2011 9:47 am

You have the API grades which start with an S (spark ignition) or C (compression ignition) followed by another letter, which the higher it is the better the level of protection from the oil. (The C and S don't actually stand for spark/compression but it helps me remember...)

Then you have the ACEA grades - A for petrol and B for diesel, followed by an increasing number dependent of performance (B3 being 'better' than B2 for example).

So for most older vehicles the oils currently on sale are way better than those available and specified when the vehicle was new.

MULLEY wrote:therefore anything that preceded this version was suitable at the time & therefore in reality it doesn't matter

To put it simply, probably! With the exception perhaps of some really old engines with white metal bearings - I believe they relied more on the presence of certain compounds in the old oils which have now been removed or reduced in the name of the environment.

Gibbo2286 · Post by **Gibbo2286** » Fri Mar 04, 2011 9:48 am

I've always used Comma oils from the nearest motor factor, supplied it to my customers too never had a problem and I've had non turbo BXs with over 300k miles on the clock. Gibbo.

http://shop.ebay.co.uk/items/__comma+oi ... 459_228459

Post by **Defender110** » Fri Mar 04, 2011 2:28 pm

mat_fenwick wrote: So for most older vehicles the oils currently on sale are way better than those available and specified when the vehicle was new.

I believe some older engines are not suited to modern fully synthetic oils because these were designed for modern engines with much more precise / finer build tolerance that need much thinner oil than some of the older multi-grades. Using unsuitable synthetic oils in some older engines can substancially reduce the oil pressure of the engine which needs thicker oil. I don't know if this applies to our cars but we do know that these engines are capable of megga miles on the specified older oils so why waste your money on some of the extremely high prices of synthetics when unneccesary.

smiffy1071 · Post by **smiffy1071** » Fri Mar 04, 2011 3:23 pm

I don't waste ANY money on engine oil at all! (hehehe) Im sure my employert won't miss it!

Gibbo2286 · Post by **Gibbo2286** » Fri Mar 04, 2011 3:39 pm

smiffy1071 wrote:I don't waste ANY money on engine oil at all! (hehehe) Im sure my employert won't miss it!

Will you miss your job when he sacks you for theft smiffy?

Instant dismissal for garage employees topping up their own engines in the lube bay is not uncommon. Gibbo.

Post by **mat_fenwick** » Fri Mar 04, 2011 4:00 pm

Defender110 wrote:I believe some older engines are not suited to modern fully synthetic oils because these were designed for modern engines with much more precise / finer build tolerance that need much thinner oil than some of the older multi-grades.

Whether an oil is synthetic or not doesn't actually affect the viscosity. It's true that if you look on the shelves the mineral oils will be thicker than the fully synthetics, but it's just because (as you say) the synthetic oils are generally designed for modern higher tolerance engines. You can get thick synthetics to directly replace older oils, even 20w50! Just harder to find. But I reckon you'd be better putting the extra expense towards changing it more frequently, rather than fully synthetic in a lowly stressed diesel engine.

smiffy1071 · Post by **smiffy1071** » Fri Mar 04, 2011 4:42 pm

Gibbo2286 wrote: Will you miss your job when he sacks you for theft smiffy?

Instant dismissal for garage employees topping up their own engines in the lube bay is not uncommon. Gibbo.

I'm not going to say where I work, but it isn't in a garage! quite honestly, more oil is spilled on the floor per day, than the 4.5 litres or so to do an oil change every month!

MULLEY · Post by **MULLEY** » Fri Mar 04, 2011 8:53 pm

Every month, you must love that engine

Mothman · Post by **Mothman** » Fri Mar 04, 2011 9:01 pm

Some very interesting comments apart from some that advocate nicking oil from ones employers, ime sure grief will come of this if continued for a long time.
Ile go and get a good quality mineral oil tomorrow morning and give the old girl a well deserved change.

However, should i use some engine flush first?

Andy

MULLEY · Post by **MULLEY** » Fri Mar 04, 2011 9:06 pm

Good question about engine flush, some say yes, others say no, so dunno tbh. I've done it myself & not noticed anything, but then again nothing was wrong anyway, so i'd save your money & only ever use it if the car had an issue with emissions.