[wi_badger]

So there was an article posted by TFL saying the 2 - I6 variants are mechanically identical and the hp/tq rating difference is only due to premium vs regular fuel.

Any way to confirm this as it seems hard to believe. I would assume there are pressure differences between the turbos or something in the computer programming.

I know someone had access to the parts diagrams. Are the turbo units the same part numbers between S and non-S variants?

 

[electroman]

Interesting point they make. I wonder where they obtained this information? @ASH8 has access to some drawings, not sure about the North American engines though.
2024 Mazda CX-90 Trims and Pricing Have Been Revealed, Starts Just Under $41,000 - The Fast Lane Car (tflcar.com):

A quick note on the power bit: Mazda’s consumer website will tell you (at time of writing) that the lesser models put out 280 horsepower and 332 lb-ft of torque. That’s only if you run it on regular 87-octane fuel. You can get the higher output running it on premium-grade fuel, including on the less expensive models.

 

[SkyActiv]

So there was an article posted by TFL saying the 2 - I6 variants are mechanically identical and the hp/tq rating difference is only due to premium vs regular fuel.

Any way to confirm this as it seems hard to believe. I would assume there are pressure differences between the turbos or something in the computer programming.

I know someone had access to the parts diagrams. Are the turbo units the same part numbers between S and non-S variants?

Car and Driver mentions it in a recent article about the CX-90.

"Turbo" models have the lower power number while "Turbo S" models have the higher power.

2024 Mazda CX-90's Inline-Six Offers Two Power Levels, 28 MPG Highway

Mazda has revealed fuel-economy and output figures for the 2024 CX-90 SUV when equipped with its inline-six engine. PHEV efficiency remains a mystery for now.

www.caranddriver.com

The 2024 Mazda CX-90 will debut with not one, but two variants of its turbocharged 3.3-liter inline-six engine. Models with a Turbo designation will put out 280 horsepower and 332 pound-feet of torque using the recommended regular gasoline. If you want to swap that swill for the good stuff, output will likely rise, but Mazda declined to say by how much.

CX-90s carrying the 3.3 Turbo S moniker will see figures rise to 340 horsepower and 369 pound-feet. Premium fuel is recommended here; regular fuel can be substituted in exchange for some power and torque, but again, Mazda didn't delve into specifics.

It's also unclear at this time if the difference between these two engines lies solely in software, or if there are some additional hardware tweaks. No matter how much power the inline-six makes, it bolts to an eight-speed automatic transmission and standard all-wheel drive.

 

[Mazda Viking]

My technical/professional side makes me think there are two different turbo models that would yield two different compressions.
The horsepower difference is too big in my opinion to be thinking it’s the same turbo with software “tweaking”.

If I do get the CX-90 it will be the normal turbo as I don’t have to pull any trailer. If there was the option of the inline 6 without any turbo, I’d pick that one.

 

[noogie]

mazda is a small company and it doesn't make sense to make two different engine. it's most likely just different ecu engine tuning.

higher octane gas will allow you to run more boost and timing in the upper rpms, which is how the higher trim yields more hp.

in other words, the low trim cx90 is running a detuned engine.

 

[wi_badger]

Agreed that it isn't different engine hardware and likely tuning differences. Would that also allow them to increase the boost pressure or would they use a different turbo? If the internals are the same then the non-S engine and transmission is being stressed less in terms of boost pressure and hp/tq.

The Mazda usa specs page has a different description for the electric motor on the S and non-S model but the hp and torque specs are the same so I don't think that is the difference.

 

[noogie]

Agreed that it isn't different engine hardware and likely tuning differences. Would that also allow them to increase the boost pressure or would they use a different turbo? If the internals are the same then the non-S engine and transmission is being stressed less in terms of boost pressure and hp/tq.

The Mazda usa specs page has a different description for the electric motor on the S and non-S model but the hp and torque specs are the same so I don't think that is the difference.

the engine ecu controls the amount of boost requested. Most likely same turbo. Most of the HP is probably from running more advanced timing in the upper RPMs. Maybe 1-2 psi more. Modern turbo chargers aren’t efficient in the upper rpms.

notice the top trim requires premium fuel. That’s because the ecu is running more boost and timing and you need the higher octane to reduce knock. More knock means more power being pulled.

 

[RAV]

So there was an article posted by TFL saying the 2 - I6 variants are mechanically identical and the hp/tq rating difference is only due to premium vs regular fuel.

Any way to confirm this as it seems hard to believe. I would assume there are pressure differences between the turbos or something in the computer programming.

I know someone had access to the parts diagrams. Are the turbo units the same part numbers between S and non-S variants?

TFL in general is quite incompetent. They originally thought the CX50 in camo was the cx60. The car had the front brake caliper on the front of the rotor, this always fwd. With regards to the straight 6, it makes 60 more hp because of premium, another stupid assertion on their part. If you look at after market ecu tunes the difference between 91 and 93 octane is 4% more hp, or 2% per point on octane. The 340 hp tune is for 91 octane since 93 is not available everywhere. So going from 87 to 91 should give you about 8% more power or 22 more hp not 60. Even if the 340 hp tune is on 93 that would put you at around 312. With the 340 hp version putting out only 103 hp per liter ( very low by turbo standards ) Iam surprised it requires premium. I suspect the turbos are the same size and the boost psi is little different. The boost must be real low, What supprises me is the premium s turbo is $7500 more than the regular premium model. The standard equipment is very similar, the s has some options the non s has and visa versa. The difference of not being the adaptive headlight on the s type. So you are paying about $7000 for a different ecu tune which costs Mazda nothing. This is bad marketing move for Mazda they could have really differentiated themselves from the competition by having the 340 hp with a 93 rating and 87 rating like they do in the 2.5 turbo.

 

[RAV]

TFL in general is quite incompetent. They originally thought the CX50 in camo was the cx60. The car had the front brake caliper on the front of the rotor, this always fwd. With regards to the straight 6, it makes 60 more hp because of premium, another stupid assertion on their part. If you look at after market ecu tunes the difference between 91 and 93 octane is 4% more hp, or 2% per point on octane. The 340 hp tune is for 91 octane since 93 is not available everywhere. So going from 87 to 91 should give you about 8% more power or 22 more hp not 60. Even if the 340 hp tune is on 93 that would put you at around 312. With the 340 hp version putting out only 103 hp per liter ( very low by turbo standards ) Iam surprised it requires premium. I suspect the turbos are the same size and the boost psi is little different. The boost must be real low, What supprises me is the premium s turbo is $7500 more than the regular premium model. The standard equipment is very similar, the s has some options the non s has and visa versa. The difference of not being the adaptive headlight on the s type. So you are paying about $7000 for a different ecu tune which costs Mazda nothing. This is bad marketing move for Mazda they could have really differentiated themselves from the competition by having the 340 hp with a 93 rating and 87 rating like they do in the 2.5 turbo.

One other thought. The 2.5 turbo puts out 12% more horsepower on 93. That would make the 280 hp 313. Now the non s is 190 lbs lighter than the type s and at its current power to weight ratio it takes 15 hp to lug around that weigh. Add this to the 313 you now have 328 hp. Paying 6k to 7k for 12 hp is a bad move.

 

[GRB60]

I disagree that the 280 HP engine will make more power on 93. The engine electronics would have to allow changes to cam timing, etc. They rated it for regular unleaded and I’d bet they did it on purpose to differentiate it from the S engine.

 

[GRB60]

There are other differences between the base model and the S. The S has the following over the base model (both in Premium Plus trim):

• adaptive headlights
• body color wheel moldings
• wheels are upgraded on the S to the pictured black/shiny finish
• second row console
• ventilated second row seats
• Premium Nappa leather
• a larger fuel tank

 

[RAV]

I disagree that the 280 HP engine will make more power on 93. The engine electronics would have to allow changes to cam timing, etc. They rated it for regular unleaded and I’d bet they did it on purpose to differentiate it from the S engine.

Then why does Mazda's own 2.5 turbo put out 227 on regular and 256 on 93. You obviously do not understand tuning of turbo engines. As it has been said before, higher octane fuel allows the car to not taper off as much boost pressure as the rpms's go up. There is something called DAM (dynamic advance multiplier) when the ecu senses potential knock it pulls timing. Mazda's 2.5 puts out the same 320 ft lbs on both fuels which tells you the boost is the same on both fuels. So the hoespower increase is all due to 93. The only real difference between premium and regular fuel is the temperature which it ignites.

 

[GRB60]

Wow. No.

 

[RAV]

There are other differences between the base model and the S. The S has the following over the base model (both in Premium Plus trim):

• adaptive headlights
• body color wheel moldings
• wheels are upgraded on the S to the pictured black/shiny finish
• second row console
• ventilated second row seats
• Premium Nappa leather
• a larger fuel tank

Not completely accurate The premium plus on the regular and s type both have nappa leather and all those other things other than the adaptive headlights do not add up to hardly any $ to Mazda. $7000 more minus adaptive headlights is a lot for a different ecu tune that cost nothing.

 

[GRB60]

Turbo premium plus:

White Nappa Leather

Black Nappa Leather

Turbo S Premium Plus:

(Quilted) Tan Nappa Leather

(Premium) White Nappa Leather

Different. Like I said.

My point was never to say the S model is a good value. Each will decide that for him or her self.

 

[GRB60]

DAM is a Subaru acronym for a feature of their turbo engine. My comments were about a Mazda.

 

[GRB60]

Octane defined:
Octane ratings are measures of fuel stability. These ratings are based on the pressure at which a fuel will spontaneously combust (auto-ignite) in a testing engine.

It is a measure of a fuel's ability to resist detonation.

You wrote: "The only real difference between premium and regular fuel is the temperature which it ignites."
That is not correct. 87 octane fuel and 93 octane contain exactly the same amount of energy.

 

[GRB60]

My last post in this thread:

I stand by my original statement. I highly doubt that Mazda's engine development team overlooked the potential of the base 280 HP engine and it can actually make more than that. They used the term "UP TO 340 HP" when referring to the S model but forgot the UP TO part on the base model?
Could it make more on 93? Probably, but only if the engine electronics (the "tune") allows it.
They made them different purposely to differentiate the models.

 

[RAV]

We can go on with this forever. A fuel becomes unstable when it heats up and ignites, therefor high octane ignites at a higher temperature as I said and is more knock or detonation tolerant.
Also, all modern cars have knock sensors where they can control timing, you are hung up on the acronym rather than the purpose of the whole conversation.

 

[ASH8]

As far as I know in Europe they will not get the CX-90, but the CX-80 3 row with the 3.0 Litre inline 6 cylinder, may have some hybridization ??

USA and Australia gets the CX-90 with the high power Turbo inline 3.3 6 cylinder and yes the Premium Fueled model get more HP and Torque over standard 3.3 Turbo,.... and YES it does make a difference as ECU will learn/map with the higher Octane rated gas.

I have not gone through Mazda EPC parts to try and glean more info and what is used for which configurations, I am getting somewhat too old to keep up (joke), and yes the EPC info I have posted is USA model.