Aygo engine oil

[Brian8]

When asked, my dealer stated that they use 0W20 oil in my wife’s Aygo.  This is contrary to the handbook which requires 0W16 oil.  The handbook even states that if 0W20 oil is used it should be changed for the lighter oil at the earliest opportunity.  Car is a 2020 with 20k miles and is now due a service (3 year - 2 previous Toyota services by previous owner).

Any recommendations and feedback or experiences would be welcomed 

[TonyHSD]

Hi and welcome. 
Ow20 it’s fine and it is very close to performance and protection properties to 0w16. Not a problem to drive with it until the next change or use this every time you service the car. The 0w16 may have slightly better fuel efficiency but we are talking about 2-3mpg, easier off set by other variables. Let Toyota take care of the service so you have another year of relax warranty. 
Regards 

[haelewyn]

Generally, it's always good to follow recommendations of the book.
What I DID read and saw are people really neglecting their maintenance scheme which is very dangerous cause there is only about 3 liters of oil in the pan and consumption can put you under minimum easily.
Nevertheless, people who neglected to change oil but added some in time managed to get high mileage on their Aygo.
Neglecting the changes could cause oil consumption or make it larger.

The above problem is a lot worse than using this 0W20 oil instead of 0W16.

Since the Aygo runs on a very old engine by now, I am sure it can run almost any kind of oil or some variation is not SO bad.
 
The complete text from the book is :
"""""""SAE 0W-16 is filled into your Toyota vehicle at manufacturing, and the best choice for good fuel economy and good starting in cold weather. If SAE 0W-16 oil is not available, SAE 0W-20 oil may be used. However,
it should be replaced with SAE 0W-16 at the next oil change.""""""""

One idea is to just do what they ask, so you never have warranty problems in the very unlikely event that your engine would go bust prematurely.
On the other hand, I wouldn't be surprised at all if dealers use 0W20 ... or put an other viscosity on the bill of what they really put in.
 

[FROSTYBALLS]

0W-20 was previously the standard recommendation for the Aygo. 0W-16 is used in other models - eg Corolla - so should be available. Try stipulating when booking the service and when dropping car off, that the correct oil is used.

[mrfixer]

Manufacturers have been moving to thinner oils for years. Its all to do with improving fuel economy by reducing energy losses inside the engine (windage and pumping losses). Every little helps.  In reality the difference between a 0W16 and a 0W20 is very small (Kinematic Viscosity of 0W16 at 100deg is about 7.5cSt vs. 8.5cSt for a 0W20). The average owner is not going to notice the difference. Don't worry about it.

[Cyker]

It probably doesn't matter much on the Aygo as it's the same 1KR-FE, but some engines have tighter tolerances and need thin oils; Thicker oils wouldn't be able to flow though the tighter gaps to where it's needed, resulting in worse engine wear. But you don't want to go too thin if the engine was designed for thicker oil, or it'll likely find its way into the combustion chamber too easily and get burned off. The moral of the story is use the oil the engine was designed for!

For reference my Mk4 uses 0w8!  

And I will give props to my dealer there, as they have always used the correct oil without me prompting them (Or at least that's what it says on the docket...!)

[Brian8]

Many thanks for all your responses.  I intend to have a word with the dealer when the car goes in for service to find out their reasoning.  I understand that 0W16 is more expensive than 0W20 - I hope a few pence saving has not been the decider 🤔

[TonyHSD]

2 hours ago, Brian8 said:

Many thanks for all your responses.  I intend to have a word with the dealer when the car goes in for service to find out their reasoning.  I understand that 0W16 is more expensive than 0W20 - I hope a few pence saving has not been the decider 🤔

Just make sure they don’t use 5w30, 0w20 it’s fine. Almost no difference between this and 0w16. , the later may add up 2mpg to the efficiency. 

[mrfixer]

1 hour ago, TonyHSD said:

Just make sure they don’t use 5w30, 0w20 it’s fine. Almost no difference between this and 0w16. , the later may add up 2mpg to the efficiency. 

5W30 is perfectly acceptable and one of the listed oils in the service manual. Anything from 0W16 through to 10W40.

The 1KR is a fairly old engine design and not too critical on oil viscosity. The reason Toyota are pushing toward thinner oils is fuel economy. The main thing with these engines is frequent oil changes. Every six months or 5k miles.