My experience using 5W-40 instead of 0W-20

Were you having problems with 0w-20? Wondering why you switched. There shouldn't be a suggestion from dealers to go away from what Toyota specifies unless there is a problem

SM-N900P ?

 

Your imagination got the best of you. The pedal is electronic - no direct mechanical connection between it & the fuel injection system. The physics between MPG drop & thicker oil is pretty straight forward. Just like MPG drop in rain - you're pushing through thicker atmosphere - and the ICE is pushing thru thicker lube ... both rob the Prius of its normal high efficiency.
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Try using a tensionometer next time said experiment is in order ... it'll remove all subjectivity, and the before & after results will coincide - guaranteed

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It could seem like the pedal is stiffer, since you need to push a little further to get the same reaction. 7 mpg further...

I wonder how 5W20 would compare to 0W20, by comparison.

 

Some portuguese Prius owners have tried 10W40 and 5W30 with no much difference. I would try an average of tanks...extending observation span.

 

Reflects what I reported years ago (not a dig at you).

The car seems much more hesitant on the thicker oil and the transition from electric to engine isn't smooth. I also couldn't get a journey average over 59 mpg UK however hard I tried on 5w30.

Now you see why it's worth paying a little extra and using the oil that is recommended for the car.

 

You probably have to accelerate harder to get the engine to turn against the thicker oil. I bet the car wasn't as fast on hills either?

 

When I bought my car used the seller (Toyota dealer) did a "cheap" service and used BMW longlife 5W40, I was trying really hard to get 4.4 l/100 km on my daily commute, I changed it before winter with Mobil1 0W20 and was disappointed because the winter took it's toll, but when the spring came I was hitting 4,2-4,3 l/100 km. You can see several tank fill ups from 2011 in my signature.

I would call it at least 3-4% (0W20 vs 5W40) lower consumption in warm weather, god knows what would happen in winter. Difference in comparison to 5W30 would be a lot less, probably 1-2%.

 

It all depends on driving style. There would be little difference with fast hwy driving, but huge difference in short trip driving with oil not up to the regular temps. Different oils for different duties. Wait, I forgot, we have only one CAFE oil in USA.

 

Hi Anas

Nice to see another Jordanian Prius owner who is suffering from the local dealer

FYI, now a days the available oil on the Toyota dealer side is the 5w 30, not even the dealer but all the other garages here, and they are trying to convince you that they have more knowledge that the manual, they says that our USA market Prius is designed to use the 0w 20 oil but the climate for Jordan is better with the 5w 30 , and if you want to make sure just read a prius manual of a Jordanian or middle east prius

i am really confused , i have a 2013 prius and i dont know to change to 5w 30 or just order 0w 20 online ?//

 

You are worrying WAY too much.
Just use what the local dealers use for everybody else and be happy.

 

Thinking about it they might have a point.

In the UK we're recommended to use 0w20 oil and our temperature ranges from -10c to 30c at the extremes. If your temp is 15c-50c then the thicker 5w30 oil might be the one to have.

I can't imagine fuel consumption is an issue in Jordan either