Does it matter what sort of oil I put in my car?

[ImADadButThatsOKIsntIt]

....and if so how do I know?

There should be some information in your car manual. You could pop to halfords if your unsure.

Yes it matters big time. What car do you drive ?

Olive could be bad....

You can Google to find out which are compatible with your car. Places like halfords sell various types.

In an emergency, any motor oil is better than none but you do need specific types for specific vehicles. If you Google you should be able to find the right one for your car.

Ford 1.8 petrol, 12 years old

Straight down Tesco’s it is!

If you put 10w40 instead of 5w30 into a 12 year old ford I don’t think it’s going to seize up. If you put bike chain oil in by mistake, then it might be more of an issue.

In other words - need more detail!

Yes it matters...
Theres loads of types and tbh even the smallest variation could potentially create issues.

There is fully synthetic, part synthetic and "proper" oil. The 5w30 etc. also denotes the viscosity of the oil at different temps, and this being incorrect could cause damage over time... My handbook even specifies a low ash oil...

Put in your reg, get your oil type: www.halfords.com/motoring/engine-oils-fluids/engine-oil

If you mean. Does it matter if you put in Castrol or Halfords own brand. No not really...

I got some in Wilko’s. They’ve got a reference book thing attached to the engine oil shelf where you can check your make, model and year and it tells you which type you need.

You can google to find this out OP. Lots of websites will have a 'finder' tool where you out your registration in and it tells you the correct engine oil. It's closed today but halfords usually have a touch screen tool that does the same or failing that a booklet.

I've no firm idea of what the 'wrong' oil would affect but why risk it when it is so easy to work out the right one.