Would there be any negative effects?

[268i]

Hey there,

I have a Yaris that I do my own oil changes on.
As many other fellow Toyota owners will see(Australia/New Zealand), in the manual it states that the car can run on many different viscocities. These include 20w-50 15w-40 10w-30 and 5w-30

Although 5w-30 or 10w-30 is the preferred choice. 30 weight oils don't come by very often or are sold at a much higher price.. Instead 5w-40 and 10w-40 is always on special. Would there be any negative impacts of using 10w-40 or 5w-40 instead?

 

[aa1986]

Only fuel economy.

 

[Triton_330]

If the manual says those weights/grades of oil can be used, then use them if you have to. I wouldn't worry about a thing.

 

[timeau]

Originally Posted By: 268i
Would there be any negative impacts of using 10w-40 or 5w-40 instead?

Don't spend money for nothing, use 10W40. You don't need synthetic for this engine. Fuel economy should be the least thing to worry about, especially on this tiny engine.
Actually, I really enjoy comments about fuel economy when the oil need to be chosen. Better than any comic TV show.

 

[dparm]

Slightly lower power output and a drop in gas mileage, and perhaps a tiny bit more oil pressure and oil temps.

The car should be fine. 40-weights wouldn't be my first choice but I suspect you won't notice a big difference.

 

[Clevy]

Isn't there a thread here from someone posting about an econobox using a thicker oil and their fuel consumtion dropped significantly. Something about the engine being unable to function properly with lean burn or something like that.
I don't know enough about them to comment accurately however if your manual says they work then I'm sure you'll be fine using one.
I know from experience that using a thicker grade in an mds and vvt equipped hemi doesn't affect the operation of those 2 systems,but I don't know for certain with a Yaris.
If the manual says it's fine then I'm sure it is.

 

[Shannow]

The thread on the Honda and amazing mileage ended when the average started to meet the expected norms. The OP was willing to share that his initial mileage improvement was statistical noise.

268i, I'm guessing being in NZ, and seeing what's happened to the Oz market that you are looking at Magnatec 10W40 ?

It's a good oil, and is what most everybody walks out of the stores with that I've seen.

Castrol make a Magnatec fuel saver 5W30 (HTHS at 3.2), which will save you a little fuel...but is like $30 more expensive...over a 10,000km oil change, you might save nearaly a tank full.

 

[Gokhan]

Originally Posted By: 268i
Hey there,

I have a Yaris that I do my own oil changes on.
As many other fellow Toyota owners will see(Australia/New Zealand), in the manual it states that the car can run on many different viscocities. These include 20w-50 15w-40 10w-30 and 5w-30

Although 5w-30 or 10w-30 is the preferred choice. 30 weight oils don't come by very often or are sold at a much higher price.. Instead 5w-40 and 10w-40 is always on special. Would there be any negative impacts of using 10w-40 or 5w-40 instead?

You can easily save 3% or more in fuel costs if you use 5W-30 instead of 10W-40. In your part of the world, that's $100 a year or more for an average driver. You do the math in figuring out whether 5W-30 is cheaper or 10W-40 is cheaper.

 

[268i]

Yea. Magnatec 10w-40 is what i've used in another toyota of mine. However, the 5w-30 fuel saver has only been recently put up onto the shelves and Castrol Edge 5w-30 or another brand of 5w-30 is usually cheaper than the magnatec's semi-synthetic offering.

This car only does around 5000km per year however. Might even just go with 10w-30 Dino (mineral) oil which is the cheapest RRP.

 

[Gokhan]

A Yaris would be fine with conventional oil. Conventional 5W-30 changed once a year should be good for driving only 3,000 miles. 10W-30 is a little thicker and has a little less fuel economy but can offer a little more margin of protection in high-speed driving.

 

[Shannow]

Is there a Repco nearby ?

Repco Oz have sales starting Thursday
Penrite Enviro+ GF5 for about the regular price of Magnatec 10W40
Helix HX-8 for $33
Helix Ultra 5W30 for $47
I think even the Repco brand 5W30 (synthetic) is around that price.

 

[gfh77665]

Originally Posted By: Gokhan

You can easily save 3% or more in fuel costs if you use 5W-30 instead of 10W-40. In your part of the world, that's $100 a year or more for an average driver. You do the math in figuring out whether 5W-30 is cheaper or 10W-40 is cheaper.
\
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Multiple posters have said there is no discernible MPG difference with the use of differing viscosities, and some of them backed it up with meticulous record keeping.

Sorry, I just don't believe 5-30 over 10-40 = $100.

 

[Shannow]

The science is there...Compare the following, and select one or the other grades, and see what the theoretical difference is.

My last OCI on the Caprice (3.8 S/C V6) was 15W40 moving to the aforementioned Magnatec Economy, mid 4s HTHS to 3.2...is getting me the anticipated 3-4% (will be going back to A3 3.5HTHS next OCI, as oil can hit 110C on the highway).

10W40 to an ILSAC 5W30 I will stand by an extra tank per 10,000 OCI.

 

[268i]

Originally Posted By: Shannow
Is there a Repco nearby ?

Repco Oz have sales starting Thursday
Penrite Enviro+ GF5 for about the regular price of Magnatec 10W40
Helix HX-8 for $33
Helix Ultra 5W30 for $47
I think even the Repco brand 5W30 (synthetic) is around that price.



Yup, although there is a repco nearby i think oz and nz repcos run different promos. Currently repco have a month long "Christmas Countdown" special which features only penrite in the mailer.
Haven't tried the Repco Brand 5w-30 Syn though. If its cheap, i might give that a try. But usually I manage to find Castrol Edge 5w-30 or another suitable oil at a good price months before I actually need to change my oil. From memory the repco RFS-5 5w-30 is around $50~NZD

 

[gfh77665]

Originally Posted By: Shannow
The science is there...
10W40 to an ILSAC 5W30 I will stand by an extra tank per 10,000 OCI.


Well, it a conundrum then. You post a chart, but again, some here have posted meticulous record keeping that shows nothing more than "background noise" with their MPG's.

Not accusing, just asking, did the posted chart come from a CAFE/government source?

 

[Shannow]

Originally Posted By: gfh77665
Not accusing, just asking, did the posted chart come from a CAFE/government source?


Nope, a lubrizol paper on lubricant trends in Europe.

Note that Europe (and Japan) have CO2 limits and taxes, which is really a variation of CAFE just the other end.

Here's my own trending from my TDI Nissan early on in it's life, with the oils that I ran...DeloCXJ was a very heavy Dino 15W40 that I was using for the first 10k, before going synthetic.

I stopped recording when I got new tyres at 40,000km (Maxxis Bravo 752 A/Ts replaced the Bridgestone Deuler HTs), and mileage suffered to the point that presious trends, on same oil were outside my scatter band on the Duellers.

 

[Gokhan]

Originally Posted By: gfh77665
Originally Posted By: Gokhan

You can easily save 3% or more in fuel costs if you use 5W-30 instead of 10W-40. In your part of the world, that's $100 a year or more for an average driver. You do the math in figuring out whether 5W-30 is cheaper or 10W-40 is cheaper.
\
\
Multiple posters have said there is no discernible MPG difference with the use of differing viscosities, and some of them backed it up with meticulous record keeping.

Sorry, I just don't believe 5-30 over 10-40 = $100.

Elsewhere in the world, gas is $10 a gallon.

If you drive a lot, with even 1% in oil-helped fuel savings, it would be about $100 a year. One can easily save about 3% by switching from 10W-40 to 5W-30; so, that's about $300 a year.

OP drives only about 3,000 miles a year. So, with his Yaris and $10 gas, he would save about $35 a year.

 

[Nate1979]

There were some major studies done by GM and others I believe around the time of test plan for SM spec (or GF-4 maybe) was introduced that showed the specific friction modifier package played a larger part than the oil viscosity when determining fuel economy effects. This very large study could not see a fuel economy difference in very controlled manner for different oil weights. I lost the link to the study but its out there on the web somewhere.

 

[Gokhan]

Originally Posted By: Nate1979
There were some major studies done by GM and others I believe around the time of test plan for SM spec (or GF-4 maybe) was introduced that showed the specific friction modifier package played a larger part than the oil viscosity when determining fuel economy effects. This very large study could not see a fuel economy difference in very controlled manner for different oil weights. I lost the link to the study but its out there on the web somewhere.

Engine friction is dominated by the bearings and friction modifiers have no effect on them as the bearings are hydrodynamically lubricated (separated by a thick oil film), meaning surface friction is not an issue. It's only determined by oil viscosity.

Friction modifiers help with the reduction of friction in parts of the cylinders and valvetrain. They help but not as much as reducing the viscosity, as the bearing friction is the dominant component.

 

[Nate1979]

Originally Posted By: Gokhan
Originally Posted By: Nate1979
There were some major studies done by GM and others I believe around the time of test plan for SM spec (or GF-4 maybe) was introduced that showed the specific friction modifier package played a larger part than the oil viscosity when determining fuel economy effects. This very large study could not see a fuel economy difference in very controlled manner for different oil weights. I lost the link to the study but its out there on the web somewhere.

Engine friction is dominated by the bearings and friction modifiers have no effect on them as the bearings are hydrodynamically lubricated (separated by a thick oil film), meaning surface friction is not an issue. It's only determined by oil viscosity.

Friction modifiers help with the reduction of friction in parts of the cylinders and valvetrain. They help but not as much as reducing the viscosity, as the bearing friction is the dominant component.


I found the study. It has a lot of details and I'm not sure I understand them all. It has probably been posted here before:

http://www.infineum.com/sitecollectiondocuments/notebooks/gf5/researchreport.pdf