Premium gas for Skyactive?

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Gooday,

I purchased a new 2018 Mazda 3 GS auto with the 2.0 Skyactive engine. I am very happy with the car, I have 20k km on it, very good fuel economy.

Some people say I should run premium fuel be ause of the direct injection in the Skyactive engine.

Is there any benefits for running premium fuel for Mazda's Skyactive technology?

Thank you!
 
Most owners will run regular in their SkyActiv engines and not notice anything. The computer will adjust the timing.

With that said, I do run 92 in my 2.5 SkyActiv and I do notice better performance and slightly better fuel economy. It's still more expensive to do though. The higher compression ratio may be a big factor in all of this.
 
I have a 2019 CX 5 with the 2.5 liter turbo Skyactive engine, The manual states that the car makes 227 HP with 87 octane and 250 HP with 93 octane but no difference in torque, And the turbo is tuned for low RPM boost to give it a lot of torque. I run 91 octane in mine which is the highest available here in CA and also quite expensive running around $4.25 per gallon at the moment.

It may be overkill but I recently retired and only put about 50 miles a week on the car at best so the cost of the fuel doesn't bother me like it would if I were commuting every day like I was a few months ago.
 
RTFM.

Mazda says 87. No need to run higher. I ran 87E10 in my M6 exclusively and it was fine.


â–¼ Fuel Requirements
Vehicles with catalytic converters or oxygen sensors must use ONLY UNLEADED FUEL,
which will reduce exhaust emissions and keep spark plug fouling to a minimum. This vehicle will perform best with fuel listed in the table.
--Regular unleaded fuel 87 [(R M)/2 method]
 
My 2018 Mazda3 has the Skyactive 2.5L engine and it calls for 87 (R+M)/2 octane. The engine is 13:1 compression ratio. I don't know if the 2.0 engine calls for the same. Also I don't know if Canada uses the RON or (R+M)/2 rating for octane. Basically, I don't know if Canadian premium is the same as US premium.

That said... This entire summer, I ran either 89 or did 50/50 fillups with 87 and 93 (average 90). This was just 1 season of testing compared the previous summer when I just ran 87. ... I saw no immediately apparent fuel economy increase and the engine does not seem to run any smoother.

I would need to repeat this test at least a few more times to get a truly meaningful result but, that will take several years to accomplish. I'm about to do an oil change and I'll collect a sample for analysis to see if there's any change in fuel dilution. Be apprised, the first analysis showed no detectable fuel in the oil.

FWIW: Since I did not see any immediate improvement in the numbers, I'll switch back to 87 and save myself 50 cents / gallon. Nothing ventured, nothing gained... It was a fun experiment -but, in my particular case, all I did was waste money.

Ray
 
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Originally Posted by wolf_06
Gooday,

I purchased a new 2018 Mazda 3 GS auto with the 2.0 Skyactive engine. I am very happy with the car, I have 20k km on it, very good fuel economy.

Some people say I should run premium fuel be ause of the direct injection in the Skyactive engine.

Is there any benefits for running premium fuel for Mazda's Skyactive technology?

Thank you!

are you referring to the type of fuel and the effects on direct injection? What does the owners manual say? You'll get much better info from the manual than you ever will here.
 
Originally Posted by Linctex
I'm curious.... what does your owner's manual recommend for octane requirements?


This. If your manual says 87, then using higher octane is just wasting your $$.
 
Like the posts above, I think running a test is in order. You may not see improved economy or power. If you do, then it's up to you as to whether it's worth it. In any case a few tanks of supreme will only add a few dollars to the overall cost of ownership.

My F150 clearly does better on Premium. I get about 1MPG more, which makes it worth the expense (to me) , as it provides extra power too. There is no guarantee of improved MPG on supreme.

Just an FYI, sometimes the station of gas you choose affects MPG. As does the season.
 
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FWIW, I genuinely believe the Mazda Skyactive engine platform is pretty darn good. There are a lot of those engines out there and the platform has been on the road for 6 or 7 years now. I follow some Mazda forums. Lots of reports of cars hitting the 150 and 200k mile mark with no engine issues at all. It seems Mazda did their homework and I personally think this engine platform is shaping-up to be a classic.
 
Originally Posted by JLTD
Originally Posted by Linctex
I'm curious.... what does your owner's manual recommend for octane requirements?


This. If your manual says 87, then using higher octane is just wasting your $$.


Unless the 87 octane has 10%+ ethanol vs premium (Shell) has 0% ethanol.
You "should" see a 3% improvement in fuel economy due to lower BTUs available in the 87 octane.
 
Originally Posted by RayCJ

FWIW, I genuinely believe the Mazda Skyactive engine platform is pretty darn good. There are a lot of those engines out there and the platform has been on the road for 6 or 7 years now. I follow some Mazda forums. Lots of reports of cars hitting the 150 and 200k mile mark with no engine issues at all. It seems Mazda did their homework and I personally think this engine platform is shaping-up to be a classic.

Can you post your UOAs of your Mazda ?

I'd run 91 octane if I was the OP. Mazda did a great job with their SkyActiv engines.
 
Originally Posted by Mr Nice
Originally Posted by RayCJ

FWIW, I genuinely believe the Mazda Skyactive engine platform is pretty darn good. There are a lot of those engines out there and the platform has been on the road for 6 or 7 years now. I follow some Mazda forums. Lots of reports of cars hitting the 150 and 200k mile mark with no engine issues at all. It seems Mazda did their homework and I personally think this engine platform is shaping-up to be a classic.

Can you post your UOAs of your Mazda ?

I'd run 91 octane if I was the OP. Mazda did a great job with their SkyActiv engines.



The base oil was Milesyn full synthetic 0w20. Be apprised, this oil has 0.33oz (10ml) of Max ZDDP and 3.5 oz of LiquiMoly #2009. Oil capacity is 4.8 quarts. Filter was a Fram Ultra. This UOA was from the first 5k OCI after dumping the factory oil at 3k. (The tested oil was in-use for 5.1k miles).

Ray


OilReport001_Mazda3.JPG
 
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I have a 2014 Mazda 6 with the 2.5L Skyactiv....it really is a fantastically designed engine and powertrain....I get about 10-12% better MPG with 91 octane Premium (non-ethanol) so its almost a wash as far as cost....It seems to like non-ethanol more than just the higher octane as the MPG gains are obvious from the few times I have found 87 octane non-ethanol gas. Once again - the most well-thought out, and innovative engine I have ever used.
 
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I am not sure premium inherently is better for these cars. I have a 2018 2.5 and when I use premium, it does seem like it has a little more low end power and I find myself being less rev happy driving old highways. However, I do notice a large increase in fuel economy when I use nonethanol premium available at most Walmart/Murphy stations around where I live. I generally see a 3-5 mpg increase and it does have noticeably more pull. Now, I am not sure it is worth the price increase of roughly 30% to get a 10-15% fuel economy increase. I have no proven results on the power. however, if I had proof showing it had an extra 10-15 hp, I would pretty much only ever run the 91 nonethanol available there. I do not know If there are similar results on lower grade nonethanol fuels as around me they are very expensive and the 91 premium at walmart is the same price.
 
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