[yaeger77]

How about for the base turbo engine? I have a preferred plus. I'm assuming only the S turbo will lower HP?

 

[CX-9to90]

I had a road trip from Toronto to north western Ontario, Canada, a couple of weeks ago. I was amazed by the fuel economy of the Turbo S.
On the return home journey, the MPG came back as 37.3 (6.3 L/100) for a back road with a speed of 50-70 km/h. For the highway, MPG was 33.6 (7 L/100)with the speed of 120 km/h on cruise control.
The i-stop was on, and the driving was not aggressive with Octane 87 gas.

 

[PhEVuser]

I started the first 6 months using Premium for my PHEV and the last 6 months using regular unleaded. Both work fine and no difference for me. Just stay with top tier gas. Reg Unleaded for the win.

 

[cx90mc]

I had a road trip from Toronto to north western Ontario, Canada, a couple of weeks ago. I was amazed by the fuel economy of the Turbo S.
On the return home journey, the MPG came back as 37.3 (6.3 L/100) for a back road with a speed of 50-70 km/h. For the highway, MPG was 33.6 (7 L/100)with the speed of 120 km/h on cruise control.
The i-stop was on, and the driving was not aggressive with Octane 78 gas.
View attachment 3062
View attachment 3061

I am happy with the MPGs also on my non S 6 cylinder but a few hand calculations showed the computer to be a little generous with the MPG figures. Even deducting 2-3 MPG I am still happy with the results. I never followed up on this as it is what it is.

 

[Sduff]

I am happy with the MPGs also on my non S 6 cylinder but a few hand calculations showed the computer to be a little generous with the MPG figures. Even deducting 2-3 MPG I am still happy with the results. I never followed up on this as it is what it is.

it has been my experience that your vehicles fuel usage gauge is always 2-3 mpg optimistic. It becomes a problem when it is 5 or more mpg optimistic like it was in my 2016 Lincoln MKZ, which is one of the reasons why I traded it in for a Kia Optima SXL.

With my normal highway driving the best that MKZ got was 24 mpg, but it said it was getting closer to 28 or 29 mpg. The Kia actually got the mpg it was supposed to get and that wasn’t on premium.

However, I now love the fact that even when I don’t plug it in my CX90 nearly matches the Kia Optima SXL and absolutely destroys it when I plug my PHEV in daily.

 

[SFCX90]

When you see the refuel trucks at the gas stations do you see 3 of them? I always see only one , unless you have some device to tell you the octane rate I would say is just marketing.

The tanker trucks have multiple chambers so a one trunk delivery could have multiple types/octane fuels onboard.

 

[Sduff]

How about for the base turbo engine? I have a preferred plus. I'm assuming only the S turbo will lower HP?

With the base turbo engine it does not matter what octane you use (as long as it is the recommended 87 Octane) it will not make more than 280hp.

To be honest, for me the only time I have ever seen a significant difference in real world driving between high or low octane fuels was when I lived at a high altitude (Over 5,000 feet above sea level).

For both my 2016 Lincoln MKZ that was rated for higher horsepower with higher octane fuel and the 2016 Kia Optima SXL I traded it in for (That WASN’T rated for higher horsepower with higher octane fuel) I noticed significant gains you could feel in both horsepower and gas mileage using the highest octane fuel (which in that state was only 91 octane, regular was only 85 octane).

However, in that same Kia Optima SXL at sea level I noticed no significant real world gains using Premium fuel. So, at sea level I just used regular in the Optima.

As I mentioned earlier, with only a 4 hp difference in the PHEV premium fuel doesn’t make sense, especially when they charge so much more for higher octane. Also, even if I owned an inline 6 CX-90 Turbo S think I would only use 87 Octane at sea level.

 

[PhEVuser]

For Mazda Engine Break in see your owners manual-

https://www.mazdausa.com/static/manuals/2023/cx-30/contents/04090100.html#:~:text=No%20special%20break%2Din%20is,a%20long%20period%20of%20time

.
For first 600 miles

• Do not race the engine.
• Do not maintain one constant speed, either slow or fast, for a long period of time.
• Do not drive constantly at full-throttle or high engine rpm for extended periods of time.
• Avoid unnecessary hard stops.
• Avoid full-throttle starts.

 

[Etex]

Interesting independent tests on top premium fuels that use Friction Modifiers in their additive package, above Top Tier standard detergent additive levels.

 

[PhEVuser]

OK, thanks.

Top Tier gas (for sure) but regular unleaded 87 octane seems to be OK for me.

 

[NewbieG]

From the experience of a long road trip to Galveston from Winnipeg Canada, when I was using the 91 unleaded offering...I would get 27-29 mpg, on the 93 unleaded...I was getting 32-35 mpg on my cx90 signature trim.

Hi hows our cx90 here in winnipeg specially in cold season?

 

[NewbieG]

And also for city driving how many Litres/100km?

 

[PhEVuser]

And also for city driving how many Litres/100km?

see post #22 for an estimate. Depends on if you have a MHEV or PHEV and how you drive. The more urban city driving with stop and go the lower the fuel efficiency. The more even the speed and less you use the throttle the better the efficiency. Flat terrain and constant highway speed is better.