is this actually "mixing" oils?

[newbie69]

Had to top up today and I used the last 200ml of Shell Helix Diesel HX7 AV 5W-30, which had been given to me from the dealers (not the wisest choice from them imo) and which according to the guys that had serviced the car is of the same spec as the one they use in all services and was ok to use for topping up. However, I still have 4 litres of Castrol Edge Turbo Diesel FST 5w-40 which I had used in an oil change I had done some time ago, when I decided to go with a slightly thicker oil as recommended by some and my questions are the following:

Given the fact that the oil currently in the car is of the Shell Helix Diesel HX7 AV 5W-30 specification, which I read is: ACEA A3/B3/B4/C3 VW 502 00/505 00/505 01 certified, would I do any harm topping up with the Castrol Edge TD 5w-40 which is also as I read: ACEA A3/B3/B4/C3 VW 502 00/505 00/505 01 certified ?

I know you shouldn't mix different types of oil, but to me it sounds as these two have the same specifications except for the summer viscosity index which is 30 for the Shell and 40 for the Castrol, so what's the case here? The manual also states the recommended oil type for fixed servicing intervals (I believe mine is on that one) is 502 00, so it should be ok using the Castrol for the coming top-ups, no?

[KeithCheetham]

Is the oil being used in your petrol VRS, the oil that you are mentioning is a diesel specific engine oil which will have additives to maintain soot etc in suspension. The Casrol Edge web site below does not appear to list a suitable oil for the Mk2 VRS.

http://castroledge.com/oil-range/oil-selector

[Guest]

A diesel specific oil of the type you describe is ok for topping up, but I would maybe never use it for a complete oil change. Is there a reason you have put in the diesel oil when you did the oil change? The reason I ask is that diesel specific oil is higher in detergents. These are needed in modern diesels for lots of reasons. Diesels rev much lower than your petrol engine. Therefore a diesel specific oil, as opposed to a non specific oil (oil suitable for petrol or diesel engines) but still meeting the same specs, does have a tendency to foam more in a higher revving petrol engine. I found this out during our testing of a new engine last year during which we bench ran several engines to destruction on different oils. The diesel specific oil in petrol engines gave the least amount of protection at high revs due to the introduction of air into the oil galleries caused by foaming. I would stick with the manufacturers recommended oil for a high performance engine such as this.

[dieselV6]

I thought more recent oils are "universal", e.g. VW 502 petrol /505 diesel, or even more recent VW 504 petrol / 507 diesel?

If an engine needs 502 oil, then both oils mentioned will be fine and you can mix them safely.

Though it is true that for oils that have "diesel" specifically mentioned in the name, the additives are likely to be better suited to diesel than petrol, exactly as Estate Man said.

Still, 502 spec is 502 spec, you can safely use both oils on 502 rated engine. With the caveat that a "non turbo diesel" oil is likely to be better for a petrol engine.

[newbie69]

Well, it also sounded strange to me to be given an oil bottle that read "Diesel" with bold letters on it straight away from the dealer the day I picked it up, being said: "If there is need to top up use this it will be fine". "But you know, here it says Diesel!" "That is not a problem."

Then I decided to change to what VW and Skoda recommend, that is: Castrol Edge, but I couldn't find a 5w-40 castrol that didn't read "Diesel" on it. (wanted to go one step thicker than 5w-30) So I contacted Opie Oils directly and, cutting his very explanatory reply short, he assured me that the Castro lEdge 5w-40 Turbo Diesel FST would be perfectly fine for this engine, and that the words "Diesel" on most oils of this type are a plain marketing trick and will not create the slightest problem in a petrol engine. He actually said this was one of the best oils to use with the 1.4 180 hp tsi even though there were other 5w-40 "petrol" oils he could sell to me, so that is how I ended up with the 5L bottle. Which I now wonder whether I should use or not when needed in the future.

Edited 22 January, 2013 by newbie69

[dieselV6]

If it has petrol 502 mark it won't create a problem, just may not be as good as an oil without "diesel" on it.

See post #3 for detailed explanation. I just clarified that it is safe to use/mix, but there may exist a more optimal oil for the engine and is likely to be without a "turbo diesel" label on it.

But unless you tow / run engine stone cold a lot / thrash it mercilessly, you are unlikely to notice any difference as the "diesel" oil you got still must meet VW502 spec.

Edited 22 January, 2013 by dieselV6

[newbie69]

If it has petrol 502 mark it won't create a problem, just may not be as good as an oil without "diesel" on it.

See post #3 for detailed explanation. I just clarified that it is safe to use/mix, but there may exist a more optimal oil for the engine and is likely to be without a "turbo diesel" label on it.

But unless you tow / run engine stone cold a lot / thrash it mercilessly, you are unlikely to notice any difference as the "diesel" oil you got still must meet VW502 spec.

Which doesn't make sense since the oil that is put in every service from the skoda dealership is already of "Diesel" type.... :think: They certainly can't say "if you don't tow / run engine stone cold a lot / thrash it mercilessly, you are unlikely to notice any difference"! I mean I would expect that the dealer provides me with an oil that will be up to the toughest job no matter what.

Having said that, the conversation is not about whether Diesel-labeled oils are 100% ok for the 1.4 tsi (or should it be??), I thought that was not debatable. It's whether 5w30 and 5w40 oils of the exact same spec (and label!) are ok to mix.

[dieselV6]

Your expectations of a car dealership are too high, they provide oil from a company they have an agreement with, not neccessarily the best oil for your car's engine.

If you put several 502 oils to the test, all will offer at least minimum (VW specified) level of protection against wear, but some will be better than others.

And yes, 5W30 and 5W40 of the 502 spec you quoted are safe to mix.

Edited 22 January, 2013 by dieselV6

[seboni121]

Some people really don't understand oil. You can mix grades, and you can mix synthetic and dino oil safely, as long as they meet or exceed the specifications of the motor you have. 1 litre of 5-40 with 4 litres of 5-30 would give you an effective mix of about 5-32. None of the oil will degrade faster, and there will be no sludge formation or any other ill effects. Mind you the only reason for ever topping up with a different grade should be the fact you are low, at home or in the middle of nowhere, and that is the only bottle of oil you have available.

[sharkrider]

lol.. my car has been serviced from 10k (44k now) with syntium 5000 SX, the special oil BMW use to service all their DIESELS I never queried because it exceeds the spec required for the vRS.. mine doesn't use oil, and never needs topping up....

as long as it meets minum spec, its fine :p

[MartynVRS]

lol.. my car has been serviced from 10k (44k now) with syntium 5000 SX, the special oil BMW use to service all their DIESELS I never queried because it exceeds the spec required for the vRS.. mine doesn't use oil, and never needs topping up....

as long as it meets minum spec, its fine :p

When I'm due a service next I'm tempted to buy some of this and they can use that instead

[seboni121]

Syntium 5000 XS is a fully synthetic lubricant with fuel economy characteristics. It protects the engine and lengthens the life of exhaust systems fitted with DPF and TWC.

CHARACTERISTICS

Thanks to low SAPS technology (Sulphated Ash, Phosphorus and Sulphur) and its latest-generation formula, Syntium 5000 XS allows:

20% reduction of the accumulation of ash in the particulate filter capable of preventing regeneration and consequent power loss;

High protection against wear of all the engine components subjected to lubrication;

Lengthening of the intervals between changes up to the maximum specified by manufacturers;

Protection against the formation of deposits and sludge;

Advanced fuel economy characteristics combined with perfect maximising of engine performance rates;

Reduction of oxidation and oil consumption.

Specification

SAE 5W-30

API SM

ACEA C3

BMW LL-04

MB-Approval 229.51

VW 505.01

[Guest]

Yes, as dieselV6 says. It's best to go with the universal spec oils rather than the diesel specific as there are differences. The diesel spec is ok for topping up but wouldn't want to use if for an oil change due to limitations at high revs, an area it isn't designed for. It has anti foaming agents in it like all oils but due to the extra detergents it carries it foams alot more at high rpm than non specific fully syn. Two oils of the same spec can very very different in their ability to protect the engine. Another good example is that you can buy VW spec 505.01 oil for PD engine in both fully synthetic or SEMI synthetic form. The semi synthetic version doesn't offer anywhere near the same level of protection as the fully synthetic version. The semi syn version goes off spec 3-4k miles earlier than the fully syn oil. That's not to say you can't use it of course. But it's not the best for your engine in my honest opinion. Syntium is a good oil but still has high detergents which may affect it's antifoaming at high rpm. Haven't tested that one so can't say.

[CRASH67]

This has got really complicated lol

I have worked in trade years and have used "diesel speicific" oil in petrols with no known issues.

Im know oil pro. And unless you know the ins and out of oils below is what i stick too and always advise my customers

First determin a recomended oil spec from the manufactur

Ie VW502 or MB228.5 blah blah.

When you by oil make sure this number is clearly stated on the packaging job done.

As for mixing i would say as long as the oil meets the same spec i could see an issue.

But out of prefrence i try not to. I always have 1l in the car and 1l in house that way im never panic for oil.

I sometimes think people other complicate the subject needlessly.

As for someones comments about dealer chossing oil thats suits and not whats best for your cars i a lil unfair but true.

Many places are can be multi franchise or part of a group, which can dictate companys used.

BUT the dealer will oil use the Correct oil spec needed.

And regardless what people say here in my eyes if the oil meets that spec it is best for the car for the use of vehicle.

[sharkrider]

Syntium 5000 XS is a fully synthetic lubricant with fuel economy characteristics. It protects the engine and lengthens the life of exhaust systems fitted with DPF and TWC.

CHARACTERISTICS

Thanks to low SAPS technology (Sulphated Ash, Phosphorus and Sulphur) and its latest-generation formula, Syntium 5000 XS allows:

20% reduction of the accumulation of ash in the particulate filter capable of preventing regeneration and consequent power loss;

High protection against wear of all the engine components subjected to lubrication;

Lengthening of the intervals between changes up to the maximum specified by manufacturers;

Protection against the formation of deposits and sludge;

Advanced fuel economy characteristics combined with perfect maximising of engine performance rates;

Reduction of oxidation and oil consumption.

Specification

SAE 5W-30

API SM

ACEA C3

BMW LL-04

MB-Approval 229.51

VW 505.01

indeed! (thanks for that) seems deisel specific, BUT is 5W-30 and exceeds the VW spec (502) for the vRS with 505.01....

This has got really complicated lol

I have worked in trade years and have used "diesel speicific" oil in petrols with no known issues.

Im know oil pro. And unless you know the ins and out of oils below is what i stick too and always advise my customers

First determin a recomended oil spec from the manufactur

Ie VW502 or MB228.5 blah blah.

When you by oil make sure this number is clearly stated on the packaging job done.

As for mixing i would say as long as the oil meets the same spec i could see an issue.

But out of prefrence i try not to. I always have 1l in the car and 1l in house that way im never panic for oil.

I sometimes think people other complicate the subject needlessly.

As for someones comments about dealer chossing oil thats suits and not whats best for your cars i a lil unfair but true.

Many places are can be multi franchise or part of a group, which can dictate companys used.

BUT the dealer will oil use the Correct oil spec needed.

And regardless what people say here in my eyes if the oil meets that spec it is best for the car for the use of vehicle.

I would tend to agree (and I'm no oil tech) I'm just going on the fact that if it equals or exceeds recomended specs its ok

I bought a litre of simple castrol magnatec (because it was minimum VW 502) as top up! I bet most on here would never dream of using such a low tech oil... I however, haven't opened the bottle *runs

[JerryT]

Ok, I thought long and hard about posting this and if anyone has any specific questions please PM me and I will try and give you an answer

Below I have attached an extract from the ACEA (European Automobile Manufacturers Association) sequences, which hopefully may offer some explanation to the oil coding.

As to oil mixing, some years ago, there was an urban myth circulating that said you should never mix oils - the theory being that you could get base oil and/or additive interactions which could cause alsorts of issues. I have experineced this, but only in systems were the oils were considerably different (e.g. hydraulic and engine oil). Also, until relatively recently engine oils were formulated more specifically for the type of fuel that was to be combusted. That said, with all the changes that have occurred in diesel fuels over the past ten years or so the oils no longer need to be as specific as they once were. From a personal perspective I would not use an oil that states it is for a Diesel engine, unless it was in an emergency. Whilst it may be suitable for a gasoline engine it will have been formulated more in line with the needs of a Diesel engine (see post 3 by Estate Man) and as such not entirely suitable.

A/B : gasoline and diesel engine oils

A1/B1 Stable, stay-in-grade oil intended for use at extended drain intervals in gasoline engines and car & light van diesel engines specifically designed to be capable of using low friction low viscosity oils with a high temperature / high shear rate viscosity of 2.6 mPa*s for xW/20 and 2.9 to 3.5 mPa.s for all other viscosity grades. These oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

A3/B3 Stable, stay-in-grade oil intended for use in high performance gasoline engines and car & light van diesel engines and/or for extended drain intervals where specified by the engine manufacturer, and/or for year-round use of low viscosity oils, and/or for severe operating conditions as defined by the engine manufacturer.

A3/B4 Stable, stay-in-grade oil intended for use in high performance gasoline and direct injection diesel engines, but also suitable for applications described under A3/B3.

A5/B5 Stable, stay-in-grade oil intended for use at extended drain intervals in high performance gasoline engines and car & light van diesel engines designed to be capable of using low friction low viscosity oils with a High temperature / High shear rate (HTHS) viscosity of 2.9 to 3.5 mPa.s. These oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

C : Catalyst compatibility oils

C1 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines requiring low friction, low viscosity, low SAPS oils with a minimum HTHS viscosity of 2.9 mPa.s. These oils will increase the DPF and TWC life and maintain the vehicles fuel economy.

Warning: these oils have the lowest SAPS limits and are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

C2 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines designed to be capable of using low friction, low viscosity oils with a minimum HTHS viscosity of 2.9mPa.s. These oils will increase the DPF and TWC life and maintain the vehicles fuel economy.

Warning: these oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

C3 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines, with a minimum HTHS viscosity of 3.5mPa.s. These oils will increase the DPF and TWC life.

Warning: these oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

C4 Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines requiring low SAPS oil with a minimum HTHS viscosity of 3.5mPa.s. These oils will increase the DPF and TWC life.

Warning: these oils are unsuitable for use in some engines. Consult owner manual or handbook if in doubt.

SAPS : Sulphated Ash, Phosphorus, Sulphur

DPF : Diesel Particulate Filter

TWC : Three way catalyst

HTHS : High temperature / High shear rate viscosity

[newbie69]

Well again, let's not discuss about mixing "Petrol" and "Diesel" labeled oils (that's why I put mixing between quotes in the topic title) because there is no such mix actually taking place! All the oil currently in the car, put in from the dealer in the last service, is already a "Diesel" labeled one. In fact, the only way to have a mix would be not to use my "Diesel" Castrol Edge and buy a "Petrol" one to top up next time I need to. What I wanted to know was whether it would be ok to top up with another "Diesel" labeled oil, of the same spec but of slightly different grade (5w30 vs 5w40). Which from what I've read is ok.

Then, it's a different point what some insist on, that "Diesel" oils should not be used in general in petrol engines. But in that case, I should be emptying the oil tank and perform a complete oil change myself by using "Petrol" labeled oil, only 2000 kms after my last service and then take the bill to my dealer, asking why they used Diesel oil in the last service in the first place. Should I be doing that? I'm not sure...

Edited 23 January, 2013 by newbie69

[dieselV6]

No, you're OK with either oil you listed, you can top up with another VW502 oil, whatever marketing sticker is on it, petrol, diesel, lpg, or electric car. VW502 is what matters.

The performance differences if any are in overall wear and likely would show up way over 100k+ miles.

For most mortals (including myself, and I frequently drive my Skodas at full power for hours at a time) , picking VW oils is really easy: You look for VWxxx spec and "full synthetic" and then for lowest price , ignoring any other blurb. If they start selling oil with a sticker "sewing-machine-only-do-not-use-in-cars oil" ;-), that is 5W-40, full synthetic, and VW505.01 spec plastered on it and costs £2/l, I still would buy and use it in the Superb,

It's just if you have a choice of oil, do not mind paying more, and want to run the car for 200k+ miles under heavy loads, you may have a better choice. But even then I still would not trust "diesel" or "petrol" marketing stickers, I'd go and compare oil specs on the Web.

Edited 23 January, 2013 by dieselV6

[Chorlton]

Also see here, item No. 15 particulalrly

http://www.briskoda.net/forums/topic/90661-16-important-oil-questions-answered/page__hl__%2Bpoor+%2Bfuel+%2Beconomy