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

Thank you for the thoughts folks

I think i will go with 5w 30 oil, but the point now, i have 0 w 20 in the engine, and the temperature here today 42 C. what is the harm ?

and for the fuel here its our biggest problem, and the main reason to get a Prius because the price of Gasoline Liter of Octane 90 is 1.2 $ (4.6$ for US gallon) and for the Octane 95 is 1.5$ (5.7$ per US Gallon), which is very high comparing to the countries around us like Saudi and Iraq :-(


our government enjoying Torturing us and they increase the fuel prices on monthly basis :-(

BTW, which one to use to the economy (for us) octane 90 or 95 ?

 

As I have posted many times, Aussie dealers are instructed to use 10w-30 full synthetic. I believe our summer conditions can be similar to Jordan. Where I live we do get occasional frosts so mornings can occasionally get down to -7 C but more like -1 or -2. In 200,000 Kms I have had no difficulties with starting and still average 4.8 L/HKms (50 mpg US ). My oil is always clear between oil changes, though tending more to amber lately.

 

With the different gas standards around the world it's hard to tell what the numbers mean, but typically: the lowest octane pump is just fine. Only a few cars with high compression engines need anything higher, to resist pre-ignition, and it would be noted in the Owners Manual.

I doubt very much that higher octane will improve your mpg, though you could try and see. Unless: the lower octanes have alcohol blend and the higher octane do not.

I'm tempted to try a thicker oil with my next spring oil change. I do a spring and fall change (Canadian 8000 km or 6 month interval, time typically governs). I guess I would take a hit, but curious how much.

 

It depends upon what the Prius is doing.

If it is mostly doing short trips, 1-5 km with an hour or so off, the 0W-20 makes sense. But it the duty cycle is higher, the 5w-30 makes more sense. I am going to suggest a test.

Do an oil and filter test with each grade (normal change interval) and then measure the mileage on level road, constant speed, similar temperature and tire pressure. Which ever one give you acceptable performance, go with it.

GOOD LUCK!
Bob Wilson

 

How about fuel economy stats on 0w20 AND then 5w30?

Over 10k miles/16k km each should clarify this matter once and for all

 

Does Jordan use RON numbers and what does your manual say?

If Jordan uses RON, then 90 = 85 AKI, too low for prius.
If Jordan uses AKI, then 90 is fine for prius (requires 87).

BTW, 5w30 is fine in any climate. 0w20 will have "slight" edge in arctic climate and short trips.

 

this reply is of the most useful one i need , i made some research and found that Jordan use the RON rating here:

Jordan Petroleum Refinery : Fuels


fortunately , i live near the Saudi borders where i can find the Saudi gasoline rated RON 95 for the same price as Jordanian RON 90

I will start using it to fill my prius ;-)

 

The whole point IS that there will BE no harm, either way.

If the oil gets TOO thin, it might not lubricate properly but that isn't really likely to happen unless you drive the engine REALLY hard.

Check your owners manual for the proper octane rating; likely that 90 is fine.

Where you live there is ABSOLUTELY no (good) reason to consider doing that.

 

If there's no harm in using the 0W, I haven't seen anything that would indicate losing 7 mpg or whatever it is, would be worth it. Has Toyota specs out anything that indicates a move to 5W or higher would be prudent?

 

7 mpg drop sounds a little high, I doubt it would be that much. One way to find out...

Owners Manuals around the world stipulate different, thicker grades, Australia for example. I doubt engine longevity is first and foremost of Toyota's concern. While it's a factor, they also are trying to get the best mpg rating possible. And, keep in mind their stand on transaxle fluid changes.

I might do this next spring. 5W20 would be the most conservative change. Or maybe 10W30? If there's a catastrophic drop in mpg, hey, I'll do another oil change, and just pour out the oil filter and reuse.

 

Is there a way to check out the oil recommendation section of the user manual worldwide, I mean, if somebody from Europe, Australia , Middle East, Far East , etc.. how have the harcopy of the manual to report here, i dont think we can find the local version online

 

I'm not sure what you are asking here. The mileage difference likely would be more like .7 MPG. And yes, I think the fact that they actually recommend different grades of oil in hot climates means that it is prudent in some conditions.

 

My stats prove otherwise. It's about 4-7 mpg per tank on average. Also, with 5w30 I was unable to get the car to get journey average over 59 mpg UK at all, however hard I tried. When using 0w20 oil I can get the car to average upto 88 mpg UK over 20 miles. It's the top end of economy where the 0w20 oil makes a difference as well as driveability issues such as the car 'stumbling' when transitioning from electric to ICE.

I personally would insist on using 0w20 at every opportunity.

 

The oil numbers 01W-02 have a specific meaning:

• "01" - is the cold temperature viscosity, a lower number has less 'thickness', the viscosity
• "02" - is the high temperature viscosity

All engines under load will produce excess heat. The thermostat and radiator fans are designed to dump the excess heat to keep the engine coolant temperature under 92C. This is the threshold that turns on the fans. So living in a hotter climate, seek oils with the same "02" number:

• 0W-20 ~= 5W-20 ~= 10W-20 ## notice the cold number, "01" can increase without a problem

What happens with a more viscous oil, the engine has to work harder, wasting energy 'stirring' the oil. This excess heat means the radiator fans have to run longer and more frequently to keep the engine at 92C or lower. Now if you insist on using a higher temperature range oil, replace the thermostat and put a small resistor in series with the thermistor. This will let the engine run hot enough to thin the oil to 0W-20. It will also encourage formation of varnish, a thick, sticky coating to further increase the internal engine friction. . . . But it is your engine.

Bob Wilson

 

I honestly find that hard to believe. A change from 0W20 to 5W30 really isn't that much difference in overall viscosity. Now there might be other factors in play too. If the 0W was loaded with friction modifiers, like moly, and the 5W was not, that might account for most of the difference you saw. And finally, I don't think the place you live is known for temperatures above 100F and pretty much nobody really recommends using a thicker oil except where it is really hot.

 

If you ever buy engine oil in jordan make sure the oil cap and seal has the oil company logo on them since nowadays most are filling up old oil containers with crappy oil and selling them as orignal

Thanks for the warning

 

The 5W number is for cold starting only, the second number is for the working oil temp. Yes, toyota states in your own manual that 0W20 may not be enough protection for heavy duty service.

 

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