0w20 oil vs 5w30

[nielshm]

My wifes 2015 Aygo has been to a large service and oilchange - non Toyota workshop. They did'nt use 0w20 oil but Elf 5w30, and now the fuelconsumption has gone up by 10%.

The car has done 40.000 miles, sommer or winter, milage has never been this low. Yesterdays fill up at Shell shows a 47,7 mpg average. It's hot and summertime, milage should be 53 mpg by now.

It is really the extra "thickness" of the oil, that can make such a difference? Driven on flat, straigt open road suddently makes 57 mpg seems difficult - 63 mpg used to be easy any time.

[FROSTYBALLS]

An earlier Auris I owned had 5W-30 instead of 0W-20, that lost around 5-6 mpg on a holiday outward/return journey. Around town the difference wasn't as obvious.

[APS]

My question here is; Why do Toyota garages insist on putting 5w30 in the car when it is not the most ideal oil? 

The manual for the Aygo quite clearly states:

"SAE 0W-20 is filled into your Toyota
vehicle at manufacturing, and it is the
best choice for good fuel economy and
good starting in cold weather.

If SAE 0W-20 oil is not available, SAE
5W-30 oil may be used. However, it
should be replaced with SAE 0W-20 at
the next oil change."

I just picked up our Aygo from the local Toyota garage yesterday and noticed in the paperwork today that they have put 5w30 in it. I'm assuming this is just a petty cost saving choice on their part as it is probably the most commonly available and cheapest grade of oil. But that is not why I take the car to Toyota for service. <grumble>

[FROSTYBALLS]

I always specify when booking the service and when taking the car in, that 0W-20 be used.

[APS]

27 minutes ago, FROSTYBALLS said:

I always specify when booking the service and when taking the car in, that 0W-20 be used.

Hear, hear. We shouldn't have to, but I will follow your example.

 

[steveo3002]

On 5/28/2022 at 11:02 AM, FROSTYBALLS said:

I always specify when booking the service and when taking the car in, that 0W-20 be used.

bet they shrug and fill it from the big container in the corner regardless 

[FROSTYBALLS]

They do fill it from the big container in the corner - containing 0W-20.

Nowadays few Toyotas apart from diesels use 5W-30, and later models use even thinner oil such as 0W-16 (Aygo, Corolla, C-HR, Prius, Rav4) or 0W-8 (Yaris).

[Parts-King]

It should always have the correct oil in it, without question. 

I have seen technicians putting the correct oil in, only for the service receptionist to tick the wrong box on the paperwork, say 5W 30 instead of 0W 20, lazy but it happens, especially with newer members of staff. This causes all manner of problems when the customer questions it and results in the oil change being done again. We have very many of those "Big containers in the corner" these days, we keep 6 or 7 bulk grades in stock

[APS]

1 hour ago, Parts-King said:

I have seen technicians putting the correct oil in, only for the service receptionist to tick the wrong box on the paperwork, say 5W 30 instead of 0W 20, lazy but it happens, especially with newer members of staff.

Yes, this is what I suspect. That said, the fact that they returned the car to me without a windscreen wiper blade even though the 'safety report' did have a check mark against it, does not instil confidence. What else have they randomly removed? Anyway, I'm diverging. That is a different issue.

[Parts-King]

Without a blade? shoddy, have a word with the service manager, unacceptable!