Toyota 2018 Vios with CVT transmission

[rumak]

The manual does not specify EXACT recommendation to change the transmission oil ;

Does anyone have that information ,,,,,, or opinion ?

[transam]

Usually 60kkm, but if you tend to fly around, then 30kkm+ to be on the safe side. The most important thing is to use their own CVT fluid. 

[HauptmannUK]

Your Vios is fitted with the Aisin K400 series CVT introduced in 2004. This transmission has been refined over the years and is probably now the best and most reliable CVT on the road. As such I understand that Toyota are now saying that the fluid is a 'lifetime fill'.  I am not a fan of this approach although I can see their reasoning.

Anyway, CVT fluid works very hard. All the power from the engine is transferred through the thin film of CVT oil sitting between the belt and the pulleys.  This film of oil is therefore under immense shear stress.  Moreover high temperatures cause the base oil to oxidise over time and the friction-modifier additives to degrade - normally felt as shuddering/juddering under load as the fluid ages.

 

If you are intending to keep the car for a long time then my suggestion would be to change the oil every 30k km, or 20k km if you routinely drive on mountain roads or tow with the car.  That may seem a low mileage but bear in mind that when you change the fluid only about half of it drains out, so you are only 'refreshing' half the fluid.

 

You transmission takes Toyota/Aisin type 'FE' fluid ('FE' will be stamped on the filler plug).  To change the fluid correctly you need to connect Toyota Techstream diagnostic  software to the car - so best to go to the Toyota dealer.

[rumak]

2 hours ago, HauptmannUK said:

Your Vios is fitted with the Aisin K400 series CVT introduced in 2004. This transmission has been refined over the years and is probably now the best and most reliable CVT on the road. As such I understand that Toyota are now saying that the fluid is a 'lifetime fill'.  I am not a fan of this approach although I can see their reasoning.

Anyway, CVT fluid works very hard. All the power from the engine is transferred through the thin film of CVT oil sitting between the belt and the pulleys.  This film of oil is therefore under immense shear stress.  Moreover high temperatures cause the base oil to oxidise over time and the friction-modifier additives to degrade - normally felt as shuddering/juddering under load as the fluid ages.

 

If you are intending to keep the car for a long time then my suggestion would be to change the oil every 30k km, or 20k km if you routinely drive on mountain roads or tow with the car.  That may seem a low mileage but bear in mind that when you change the fluid only about half of it drains out, so you are only 'refreshing' half the fluid.

 

You transmission takes Toyota/Aisin type 'FE' fluid ('FE' will be stamped on the filler plug).  To change the fluid correctly you need to connect Toyota Techstream diagnostic  software to the car - so best to go to the Toyota dealer.

good info and opinion.    I am curious as to why you say  " I can see their reasoning"  ....... for the lifetime recommendation.     I called a Toyota mechanic (thai)  that i know and he said 60 K  would be good.     A friend that bought a 2019 model told me they said lifetime .  He has 100 k  km on his odometer.     I think i will go with the 30 k  suggestion ...... can't hurt unless they forget to put the plug back in   ????

[HauptmannUK]

6 hours ago, rumak said:

good info and opinion.    I am curious as to why you say  " I can see their reasoning"  ....... for the lifetime recommendation. 

This is a well-proven and durable transmission. Even without a fluid change most units will likely be capable of achieving 200k km with minimal reduction in drivability.

Toyota's thinking will be that specifying a fluid change at, say, 50k km increases the likelihood of failures. The reason for this is that many (most?) fluid changes will be carried out outside the dealer network. There are several specifications of CVT fluid on the market, not to mention ATFs - many customers will end up with the wrong fluid and cause transmission damage. Correct replacement also requires the use of Techstream, which few independent repairers will have. Over a 200k km distance four fluid changes would take place - the chances of something going wrong are quite high.

From my experience in the UK the biggest problem is that drivers use standard Dexron ATF in CVTs...

[DaRoadrunner]

Considering that oil costs a lot less than a new transmission, I always change mine more frequently than recommended. Use the correct specification oil. Beware of some unscrupulous gas stations that use cheap poor quality oil. Check it comes in the manufacturer's bottle and not out of some unmarked oil drum round the back of the garage. Safest bet is to use the franchised dealer.