0W20 vs 0W30 oil

[diy_fun_uk]

Bought myself a 2015 Honda Civic 1.8 petrol. I always like to keep a litre of oil in the car to top up. Manual states to use:

0W20, meeting standard ACEA A3/B3, A5/B5

However it also states if 0W20 not available, 0W30 can be used. To confuse matters, when Googling, some are saying 0W20 is generally too thin and 0W30 is better!

When I use the Shell oil checker, it recommends a 0W20 oil meeting ACEA C5 C6 specification.

When I use the Halfords oil checker, it also recommends a 0W20 oil meeting ACEA C5 C6 specification. However it also recommends a 0W30 oil meeting A5 B5 specification.

I don't have a Honda dealer on my doorstep (lazy!) so just want to buy something from Halfords if possible. I don't want to overthink this (it's just a litre to keep for top up) so are any of the above ok for my to buy?

 

[accelerator]

If the manual states either 0w20 or 0w30 can be used, then either should be fine.

According to Copilot search, both have the same cold-start viscosity, but the 0w30 has a higher viscosity at operating temperature, giving slightly less fuel economy but more protection, and may therefore be better for an older engine.

 

[carmanmemoranda]

Yes. Any oil is better than no oil, but always stick to recommended oil when possible

Personally depending on how many miles it's done, id go for 0/30 if it's higher mileage.

The higher number denominates the characteristics of a 20 or 30 weight oil. It doesn't mean the oil gets thicker, it means it performs like a 20 or 30 weight oil would do when hot.

 

[robinbanks]

In this climate I don't expect 20 or 30 rated will make a meaningful difference. Go with the spec

 

[carmanmemoranda]

In this climate I don't expect 20 or 30 rated will make a meaningful difference. Go with the spec

Both are specced.

There's no doubt that 30 will give slightly better protection with wear

 

[diy_fun_uk]

I'm sure life used to be more straightforward when buying oil!

Now when perusing the various makes, some say 'suitable for Alfa Romeo, Fiat', or 'Volvo' or 'Audi, VW' etc etc. In a way I think that could be confusing for the consumer. State the type (e.g. synthetic), the viscosity (e.g. 0W-20) the quality (e.g. ACEA) and leave car brands out the equation. I'm obviously not referring to brands of the vehicle manufacturer themselves.

 

[carmanmemoranda]

I'm sure life used to be more straightforward when buying oil!

Now when perusing the various makes, some say 'suitable for Alfa Romeo, Fiat', or 'Volvo' or 'Audi, VW' etc etc. In a way I think that could be confusing for the consumer. State the type (e.g. synthetic), the viscosity (e.g. 0W-20) the quality (e.g. ACEA) and leave car brands out the equation. I'm obviously not referring to brands of the vehicle manufacturer themselves.

Pretty good summary, but the points needed in order are.

The quality and spec, then the viscosity, then whether it's fully, semi or mineral.

The label/brand means very little, but some brands will exceed the above requirements, and some will meet them.

I'm not going to get into a which brand is best though, because there is no simple answer. It varies.

 

[diy_fun_uk]

Pretty good summary, but the points needed in order are.

The quality and spec, then the viscosity, then whether it's fully, semi or mineral.

The label/brand means very little, but some brands will exceed the above requirements, and some will meet them.

I'm not going to get into a which brand is best though, because there is no simple answer. It varies.

The Halfords oil checker suggests this based on my reg:

TotalEnergies Quartz INEO Xtra Long Life 0W/20 1L. Fully synthetic, ACEA C6 C5.
Castrol Edge Titanium Volvo 0W/30 1L. Fully synthetic, ACEA A1/B1, A5/B5.

So based on these I might be better opting for the Castrol as it matches the ACEA spec as per the car manual?

 

[norseman]

Buy the listed spec. from a reputable refiner .. don't pay for the label.

Agreed the OW-30 will give better wear protection, which is more important than any possible saving on fuel consumption.
Regular oil changes are vital, even on high mileage engines.

 

[carmanmemoranda]

The Halfords oil checker suggests this based on my reg:

TotalEnergies Quartz INEO Xtra Long Life 0W/20 1L. Fully synthetic, ACEA C6 C5.
Castrol Edge Titanium Volvo 0W/30 1L. Fully synthetic, ACEA A1/B1, A5/B5.

So based on these I might be better opting for the Castrol as it matches the ACEA spec as per the car manual?

Yes

 

[Scally-Ho]

My wife's Suzuki has been running on 0W 20 oil from new and the car is now 10yrs old. I've never had any bother buying a 5L can and the advantage is obvious during very cold weather and the eager cranking speed ensures the engine fires first turn of the key. The car's manual did mention 5W 30 was acceptable if the lower viscosity oil was not available, but I've never experienced that problem.

 

[JohnD]

....To confuse matters, when Googling, some are saying 0W20 is generally too thin and 0W30 is better....

There's a lot more to be said for reading the manufacturer's recommendations, than randoms on the 'net.

 

[Harry Bloomfield]

I'm sure life used to be more straightforward when buying oil!

Now when perusing the various makes, some say 'suitable for Alfa Romeo, Fiat', or 'Volvo' or 'Audi, VW' etc etc. In a way I think that could be confusing for the consumer. State the type (e.g. synthetic), the viscosity (e.g. 0W-20) the quality (e.g. ACEA) and leave car brands out the equation. I'm obviously not referring to brands of the vehicle manufacturer themselves.

That, is exactly what I have always done. If you take your car to be serviced, that is what the garage will do (if you are lucky).

 

[carmanmemoranda]

My wife's Suzuki has been running on 0W 20 oil from new and the car is now 10yrs old. I've never had any bother buying a 5L can and the advantage is obvious during very cold weather and the eager cranking speed ensures the engine fires first turn of the key. The car's manual did mention 5W 30 was acceptable if the lower viscosity oil was not available, but I've never experienced that problem.

A lot of cars are very flexible on their oil requirements.

Some (wet belt engines are a good example) are very VERY demanding on the oil required.

 

[carmanmemoranda]

That, is exactly what I have always done. If you take your car to be serviced, that is what the garage will do (if you are lucky).

Always simple enough to ask them what oil they will use.

Usually it will be, " whatever the engine requirements are" or "1 of those 2 or 3 barrels we've got over there"

From the answer given you will know the garage quality level.