Mixing engine oils

My van handbook says the engine oil should be 0W-30 but the garage put 5W-30 in it.

I suppose if they drained it and filled up with the new stuff it’ll be okay. But if I top it up with 0W-30 will the engine grumble with the mixing?

No will be fine

it won’t care, you’ll ned up with something like 4.8w-30

however, i would say that depending on the engine certain oils to contain/do not contain chemicals that can effect longevity of things in modern engines, ie wet belts etc, so it could be prudent to ensure the correct oil is used if suitably modern…I’m talking more manufacturer spec than viscosity

Me, on my 15 year old Mazda, it gets whatever semi quality oil i can get my hands on at a decent price, and regularly

I think they are very similar but with different temperature ranges. Is that correct?

My van handbook says the engine oil should be 0W-30 but the garage put 5W-30 in it.

There’s often a range to account for using the van in Dubai or Derby. The oil must conform to manufacturer’s spec, e.g. VW 508.00/509.00

0W would be better in winter in Derby

It’ll be fine

I’ve mixed engine fuels before in my van (a slightly f__kwitted unleaded/diesel mix), and it was fine too. I wouldn’t necessarily recommend doing that though.

A wise man once told me that engines die from a lack of oil, not a mix of oil.

It’ll be fine. Just top up with the ‘correct’ oil when needed.

it won’t care, you’ll ned up with something like 4.8w-30

however, i would say that depending on the engine certain oils to contain/do not contain chemicals that can effect longevity of things in modern engines, ie wet belts etc, so it could be prudent to ensure the correct oil is used if suitably modern…I’m talking more manufacturer spec than viscosity

Me, on my 15 year old Mazda, it gets whatever semi quality oil i can get my hands on at a decent price, and regularly

+1, the oil viscosity only impacts how it behaves when cold or hot, e.g. hot countries tend to specify a heavier oil like 20W-50 whereas cold countries will specify 0W-30.  The worst that will happen is it’s a bit harder to start on a really cold day, but unless you live in Aviemore the odds are it’ll never be as cold as it was intended to function in anyway.

I would be worried about what spec was used though.  For some engines it’s fairly trivial because they don’t do anything unusual.  Others with wet belts, or some unusual bushing / coating material, emissions control systems, etc need very specific oils, not just whatever generic Castrol 5W30 the garage had in a 42gal drum.

A wise man once told me that engines die from a lack of oil, not a mix of oil.

The engine will doubtless be fine, but the turbo, DPF and all sorts of other things could end up goosed – when you take it back to the mechanic with faults later down the line  they’ll blame the van rather than their servicing. What van / engine is it? And what, beyond viscosity does it day about oil in the handbook?

The problem with the ‘wise men’ in the motor trade is they tend to tell they customers that the problem is always ‘modern engines’ while using their cheque books to solve probems, and that the issue is not that their skill set being 20 years out of date. They seem to be very well rehearsed as selling that ineptitude to their customisers as ‘wisdom’ 🙂

The handbook may well be out of date as well, the specs do change with time. Check what the current recommended spec is online.

The handbook may well be out of date as well, the specs do change with time. Check what the current recommended spec is online.

Just found out this is the correct answer. It’s a 72 plate Movano 2.2 140 (Pug Boxer in a Vauxhall dress). Apparently the manufacturer has changed the oil spec from 0W-30 to 5W-30 this year and the dealer just follows the manufacturer spec. Apparently it happens a lot.

Every day is school day

It’ll be fine. Engines can run a range of oil weights acceptably, if not ideally.

Its important to remember that there is much, much more to an oil spec than ‘5w30’, which is something that is completely lost on most garages and why I would only ever DIY it or supply my own oil.

Additivies, content of certain metals, ash content, etc etc, all very specific.

The important take away from this thread – the most typical time for this question to be asked is when said car needs a top up.

At which point(as highlighted up there) – Enough oil, is far, far, far more important than ‘the right’ oil.  Even if you had the worlds most highly strung, exotic, mixed materials and fussy engine that needs a one-manufacturer unicorn tears oil spec, and you got a low oil warning on the motorway – you’d still better top it up with the worlds shittest litre of generic crap bought from the service station, than leave it low.

The handbook may well be out of date as well, the specs do change with time.

It’s a 72 plate Movano 2.2 140 (Pug Boxer in a Vauxhall dress)

I’ve got the same van – without the dress I guess (Boxer – I feel naked now)

In peugot guise in place of a handbook it comes with an app, so for things like  spec changes over time you’re alway up to date becuase…… if you look you the spec for oil the app just tells to call a dealer and ask them 🙂

ElShalimo
Full Member

Apparently the manufacturer has changed the oil spec from 0W-30 to 5W-30 this year and the dealer just follows the manufacturer spec. Apparently it happens a lot.

It does… I was bored and went on a bit of a dive on one of mine and it’s had 3 different engine oils recommended since it was built, and 2 different gear oils. I managed to track a couple of the changes back and found it was just that the manufacturer had retired some products and switched all the cars that used those onto a newer one (because the newer cars were pickier about oil while the old ones are happy on either the new oil or the old). Not a performance led thing at all, for my car, just product line thinning/economies of scale.

Oil grade’s never likely to hurt you unless you go crazy but you do sometimes have to get the actual spec just right.

I’m getting concerned about @maccruiskeen’s nekked van.

The oil must conform to manufacturer’s spec, e.g. VW 508.00/509.00

… is the right answer.  xWy isn’t really all that relevant.  What is relevant is that it meets the specification number dictated by the car manufacturer.  If you’re buying a top-up bottle then all the standards will be listed in Flyspeck 3 on the rear label.

IANAmechanic.

There is a new Stellantis 5w30 engine oil specification – fpw9.55535/03.

This is now used in all 1.5 diesels, and supercedes all previous recommendations. I need it for my Vauxhall Combo Life. I don’t know about the Movano, but for the Combo the exact spec. is important.

Those different specification codes might mean something as significant as fully synthetic or semi synthetic if it’s an older design engine. It’ll definitely mean a different additive package for specific applications, so yes, that’s far more important than a negligible change in viscosity.

Likely the reason behind a lot of those Ford ‘Ecoboom’ wet belt failures.

(IAA mechanical engineer looking after lubricant contracts for an industrial site).

Oil pros know to match the correct ACEA spec oil to the engine spec and then viscosity is a climate-based choice.  It cuts out a load of marketing crap when trying to be certain the right oil is in the engine.

I think for a Movano 2.2 it is a C2 spec so any C2 will be fine if you want to cross-check.  The ACEA spec covers ash-producing compounds (so you don’t kill the emissions equipment) and high temp / high shear viscosity which is a bit more specific (and pertinent for modern designs) than the second number in an SAE spec and is related to the bearing clearance tolerances in the engine design.

The first number in the SAE spec is the “W” (winter) rating and it covers cold viscosity behaviour.  Every oil is “cold” at startup and it has to be pumpable and useful in the engine.  Don’t worry about 5w vs 0w.  Even a 10w is pumpable at minus 30 and a 0w only extends that to minus 40.

Synthetic and any other marketing jargon are just that.  They’re selling messages.

Manufacturer specifications “may” encompass some more specific requirements than the international specs but typically they’re just white-labelling an ACEA spec.