Mixing engine oils

[CarterH]

Hi all, I usually keep a small bottle of engine oil at home to top-up if needed (Skoda Rapid, 2014, 1.2ltr, 77kW). However, with a recent oil change, the service dealer added a different oil: Mobil Super 3000 Formula V 5W-30 (previous oil was Valvoline SynPower XL-lll 5W-30).

 

When searching online, I could only find 5 litre buckets of that, which is more then I would need even for a complete oil change... I also found statements ranging from "Yes, you can mix different brands of engine oil" to "You should NEVER ever do that!".

 

So my question is: can I use a different oil to top-up the current Mobil Super 3000 Formula V 5W-30 and if so, what parameter are important?

[Mickvrs220]

Ive always done same as you ,stayed on spec but have used different brands ,usually when the top up oil warning pops up when away on hols ,hate having lights on dash haha ,never had a problem with mine 👍

[xman]

Both oils quoted above meet VW504.00 specifications which is the recommended spec for the OP's engine oil.

 

You can mix brands even weights to your hearts content as all but exotic PAO oils are fully miscible.

 

Stick to a vw 504.00 specification oil to maximize the possibilty of a long trouble free life for your engine. Look for the specification printed on the container.

 

Might say approved to or meets the requirements of. But thats a debate for another day.

 

 

[MickA]

I use 5w 30 Castrol to the VW spec posted above in my Toledo (same 1.2TSi engine) 

Because you only get the Castrol in 4 litres containers, which is a perfect quantity for the oil change I use a Mobil 5w 30 for top ups. The Mobil oil is used in my Mazda (to Ford spec) probably only top up by around half pint between oil changes.

[xman]

Very few brands actually are involved in refining, many not even involved in final blending. Different brands can actually sell the same product but with their different packaging/labels.

2 cans of the supposedly same brand/product may come from completely different countries/suppliers using different base oils and additives needed to enhance them to the required spec. If you scrutinise labels/pour dates/codes you'll typically find a 1 litre can may be from a completely differen source to a 5 litre can of the same product. And it changes month to month.

 

So the thing you should really concentrate on are the approvals.

"Meets the requirements of" is not the same as "Approved to"  The former being "trust me when I say" the latter is "I have a certificate to prove"

 

Unknown/obscure brands or premium product purchased via dodgy channels may not even be what they claim.

 

Buyer beware.

 

[EnterName]

On 06/08/2023 at 14:49, CarterH said:

Hi all, I usually keep a small bottle of engine oil at home to top-up if needed (Skoda Rapid, 2014, 1.2ltr, 77kW). However, with a recent oil change, the service dealer added a different oil: Mobil Super 3000 Formula V 5W-30 (previous oil was Valvoline SynPower XL-lll 5W-30).

 

When searching online, I could only find 5 litre buckets of that, which is more then I would need even for a complete oil change... I also found statements ranging from "Yes, you can mix different brands of engine oil" to "You should NEVER ever do that!".

 

So my question is: can I use a different oil to top-up the current Mobil Super 3000 Formula V 5W-30 and if so, what parameter are important?

Why not buy a litre of two from the dealer?

[HenPen]

Last February I upgraded to a new 2023 2 litre diesel Octavia from an 2014 Octavia diesel. This week the oil needed topping up. I opened a bottle of Castrol Edge 5W-30 (VW 507) which I had left over and 1/2 litre in. Then I happened to look up the details of the newer VW 509 oil specification. Apparently using any of the previous oil spec  "will cause permanent and irreversible damage to the engine". So I have had to have the oil drained and replaced with the higher spec. I have been kicking myself: ALWAYS READ THE MANUAL, STUPID!!!