CX-50 Turbo octane?

biglou

Member
I have a Turbo model and was wondering what kind of fuel you guys are using and are you happy with the performance. I'm running midgrade (89 octane) and its peppy with decent gas milage. but I'm wondering if I'm wasting my money and should just use regular. I'm not a speed demon but like the power when I need it. I posed this question to the service manager during the cars first oil change and he said I was wasting my money. The turbo was designed to run on regular. Not sure if I'm buying his story. Appreciate any feedback
 
I have a Turbo model and was wondering what kind of fuel you guys are using and are you happy with the performance. I'm running midgrade (89 octane) and its peppy with decent gas milage. but I'm wondering if I'm wasting my money and should just use regular. I'm not a speed demon but like the power when I need it. I posed this question to the service manager during the cars first oil change and he said I was wasting my money. The turbo was designed to run on regular. Not sure if I'm buying his story. Appreciate any feedback

The HP and toque are similar below 4000 RPM on all fuels. With 93 octane, the HP and torque does not drop off. The issue is the transmission under most conditions shifts well below 4K. You have to drive in sport mode and with a heavy pedal to get the most out of it.

Also, see this as it is is directly related to your question:



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I used put premium fuel in my '18 Mazda6 Signature every fill up. But decided not to do that on my last two rigs with the same engine. My drive is 95% highway and I am on the road very early, so it's a chill highway drive into the city.
I will say the once a month or so time when I am foot-to-the-floor, I really miss the top end pull with the higher spec fuel but that's such a rare occurrence that it doesn't bother me.
The engine doesn't like to rev out anyways, so I am fine with using regular fuel and just pretending it's a diesel ;)
 
I have the CX-9 with the 2.5T. I used to fuel with 91 exclusively because I can't get 93 here, but now I fuel with 87 most of the time. As everyone else has mentioned above, the higher octane only makes a difference above 4k RPM, so if you're rarely in that range, it's basically a waste of money. In the winter I use only 87, as there is no reason for me to be accelerating that hard in snowy/icy conditions. In the summer I'll fuel with 91 if the price is reasonable or if I can get it for free (sometimes the pumps run out of regular fuel and you can get 91 octane for 87 prices). I can get good use out of 91 because my commute includes a couple of opportunities to wind out the engine on a couple of highway merges on relatively clean and dry roads. I would say run 87 or 91+, just try to stick to top tier brands.
 
I'm going to try regular for awhile and see how it performs. Gas prices are on the rise here in NY again
 
Simply put - that is not totally accurate. True, few of us drive foot-to-the-floor very often so most of the time we don’t see a difference - or do we? Higher octane fuel‘s raison d‘etra is to reduce preignition, and when the ESC senses detonation it pulls timing, quite a bit in fact. This reduces power noticeably, and not just at WOT. Even half throttle with engine speeds below 2500 rpm can cause preignition and reduce power. My 2.5 turbo pulls up to ten degrees more timing using 87 versus 93 octane with a quick half pedal thrust when cruising at 2500 rpm (using a BlueDriver scanner) . This is not huge but it is noticeable to me and effects the responsiveness of the vehicle even at lower speeds.

But since most drivers are not very sensitive to their vehicle’s performance, or don’t care much about it, using the lower grade makes sense for them. Heck, hundreds of thousands of Mazda CX owners are perfectly happy with the 187 hp engine and think that the turbo 2.5 is a waste of money.
 
Simply put - that is not totally accurate. True, few of us drive foot-to-the-floor very often so most of the time we don’t see a difference - or do we? Higher octane fuel‘s raison d‘etra is to reduce preignition, and when the ESC senses detonation it pulls timing, quite a bit in fact. This reduces power noticeably, and not just at WOT. Even half throttle with engine speeds below 2500 rpm can cause preignition and reduce power. My 2.5 turbo pulls up to ten degrees more timing using 87 versus 93 octane with a quick half pedal thrust when cruising at 2500 rpm (using a BlueDriver scanner) . This is not huge but it is noticeable to me and effects the responsiveness of the vehicle even at lower speeds.

But since most drivers are not very sensitive to their vehicle’s performance, or don’t care much about it, using the lower grade makes sense for them. Heck, hundreds of thousands of Mazda CX owners are perfectly happy with the 187 hp engine and think that the turbo 2.5 is a waste of money.

I tend to agree with this, as there is clearly a slight difference with the higher octane fuels. But it is subtle, and nothing like the difference above 4K.

You can feel it the best in 3rd.
 
Thanks for the video. Confirmed what I thought and read. I've been running regular fuel for a few weeks and have not noticed any performance issues. This car still has plenty of zip at 227hp. Money in my pocket and to boot mpg has stayed the same.
 
I have a tuner on cx-5 but when it’s not on, I still put in premium fuel. I rarely use regular. I ran test and I am 100% sure there is no better gas mileage by running 87/93 or 94. When the tuner is not I still run 93. During summer months I run 93 or 94 as I drive the car hard. Plus I run, k&N reusable filter, red line water wetter, and Lucas oil, 10130 pure synthetic oil stabilizer, synthetic blend oil changes every 3k or 3 months. Finally once a year, I run, CRC turbo and valve cleaner straight into the throttlebody.

And for those who are interested in mods like intakes and exhaust, you get more bang for your buck by putting in premium fuel, compared to a simple intake or axle back exhaust!​

 
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