[Shooter41]

I just don't understand you guys that use 87 octane. I use whatever the manufacturer recommends for all my vehicles. They don't make these recommendations just for sh*ts and giggles. If you can afford an MDX you can afford to put the correct fuel in it.

 

[BLS]

2022 AWD Base model. Running 93 octane top tier gas only. 95% normal mode. Getting 20-21 in town and 22-23 on highway. Noticably better than our previous Mazda CX-9 with 3.5 engine.

 

[TexasBlueAspec]

I just don't understand you guys that use 87 octane. I use whatever the manufacturer recommends for all my vehicles. They don't make these recommendations just for sh*ts and giggles. If you can afford an MDX you can afford to put the correct fuel in it.

You don’t understand that we own multiple J35Y vehicles that use 87octane and somehow the MDX is a special outlier with about the same horsepower rating ? What’s so hard to understand?
I went from owning expensive 400HP+turbo BMWs and filling up with 93 octane for years. That’s where it counts. Not the 285hp vs 290hp tune they went from for the J35Y. I still own one Bmw manual 6-spd and use 105octane (E85) . Honda / Acura could always make their cars flex fuel to allow it but won’t . They would need to change the hoses in the tank. Either way , they tuned the vehicle to take 87 with it retarded and probably back down in that range of 280HP. You can’t even feel a difference , and it makes no difference in mileage. You could even look at the 23’ pilot and see if it says 87 or 93.
anyway, off my soapbox. I’ll report back when I get 150,000 miles and I’ll trading in my MDX.

 

[Shooter41]

There

You don’t understand that we own multiple J35Y vehicles that use 87octane and somehow the MDX is a special outlier with about the same horsepower rating ? What’s so hard to understand?
I went from owning expensive 400HP+turbo BMWs and filling up with 93 octane for years. That’s where it counts. Not the 285hp vs 290hp tune they went from for the J35Y. I still own one Bmw manual 6-spd and use 105octane (E85) . Honda / Acura could always make their cars flex fuel to allow it but won’t . They would need to change the hoses in the tank. Either way , they tuned the vehicle to take 87 with it retarded and probably back down in that range of 280HP. You can’t even feel a difference , and it makes no difference in mileage. You could even look at the 23’ pilot and see if it says 87 or 93.
anyway, off my soapbox. I’ll report back when I get 150,000 miles and I’ll trading in my MDX.

There are plenty of benefits to using premium gas besides the small power bump. I guarantee you that's not the only reason Acura recommends it. But hey, you do you, no matter how moronic it seems to me. The only circumstance I could understand is if you have a short-term lease. Then you can treat it like a rental.

 

[Hogan773]

There


There are plenty of benefits to using premium gas besides the small power bump. I guarantee you that's not the only reason Acura recommends it. But hey, you do you, no matter how moronic it seems to me. The only circumstance I could understand is if you have a short-term lease. Then you can treat it like a rental.

What are some of the other "plenty of benefits" to using premium gas in this Acura whose J35 engine is also running 87 in other Hondas? And as you answer keep in mind that Acura has "recommended" it rather than using the other "r word" (Required)

Please don't invoke the "if you can afford an Acura then you can afford to waste money on premium gas" argument too. That isn't a scientific reason for using premium gas. I could afford to supplement the heat in my house by burning dollar bills in the fireplace and it would create heat, but I don't.

 

[Shooter41]

What are some of the other "plenty of benefits" to using premium gas in this Acura whose J35 engine is also running 87 in other Hondas? And as you answer keep in mind that Acura has "recommended" it rather than using the other "r word" (Required)

Cleaner injectors/fuel system for starters. Premium gas is well-known to have more detergents in it than lesser grades. Less carbon build-up for another. I am an engineer but not at Acura so I'm not privy to exactly why they recommend it.

I could afford to supplement the heat in my house by burning dollar bills in the fireplace and it would create heat, but I don't.

That's the most pathetic attempt at a flex I've ever seen. I mean, just dollar bills? You must be a poor. We burn twenties in our fireplace.

 

[OldFart]

Just finished a 776 mile run from CT to MI. 93 octane. 75mph ave speed using ACC. Normal mode. ‘23 Advance (non S) AWD. Outside temps between 25 and 40 Fahrenheit. I averaged 22.6 mpg.

Hand calc’d mpg on a couple tanks and MDX’s computer calc seems pretty accurate.

Same trip coming back. Ave was 25.0. Outside temp averaged 55, so warmer weather must have helped. Closer to expectations.

 

[IanCH]

Everybody knows that $50 bills have the highest BTU/$ ratio, and plus you get a cleaner burn from the ghost of Ulysses S. Grant who was a chimney sweep in his teenage years.

 

[TexasBlueAspec]

Cleaner injectors/fuel system for starters. Premium gas is well-known to have more detergents in it than lesser grades. Less carbon build-up for another. I am an engineer but not at Acura so I'm not privy to exactly why they recommend it.



That's the most pathetic attempt at a flex I've ever seen. I mean, just dollar bills? You must be a poor. We burn twenties in our fireplace.

You are an engineer yet you made some simple mistakes. ( all engineers do).
You assumed 93’ octane premium has anything to do with detergents. Detergents are added by supplier brand. Octane rating is the method by which they refine the gasoline. It’s a standard similar to people saying “mil-spec”.
You also came in hot throwing in the “engineering”. That works on most other forums but most of the people here who are spending money on bmws/Acura’s/Audi/Lexus/ etc are making 100,000+ and have titles equal or higher than that. Titles also mean that we refined a discipline but we can also read /write/comprehend other disciplines without needing another title to make our opinion known as well as our results posted.

If you really want the answer, the manual states the use of LESS than 87 octane will lead to damage. They “recommend” 91 or higher. Key word “recommend”. As stated again, no check engine lights, no mileage difference, no noticeable difference in performance.

so key takeaway here is
86 engine damage
87 works
91 recommend
93 throwing money away
105 ethanol not supported
XX% Flex/blend not supported higher than 15%

 

[IanCH]

Yeah so all the tuners that offer 10-20% more power on their tunes for 93 over 91 are just gatekeeping folks in california. Got it.

Yes the stock engine can adjust to run 87, not its not as powerful or efficient.

 

[TexasBlueAspec]

Yeah so all the tuners that offer 10-20% more power on their tunes for 93 over 91 are just gatekeeping folks in california. Got it.

Yes the stock engine can adjust to run 87, not its not as powerful or efficient.

Tuners can take it to the ragged edge to offer more HP, as you mention 10% or 20%. The only thing octane is preventing is detonation at that ragged edge.
What are we taking about here with the MDX HP? A few HP and possibly 2% or 3%?
The factory “tune” has the lowest grade of gas factored in . When speaking of tuning , think of your wipers going back and forth. The center is 0 .
-\0/+
The factory tune can compensate drastically to add fuel or pull fuel , as it could also change timing. When it gets outside of those \_/ parameters is when a check engine light comes on because the computer cannot compensate enough to stay happy. Which is why I reiterated that 87 is still acceptable and does NOT throw a Check Engine Light.

 

[IanCH]

Tuners can take it to the ragged edge to offer more HP, as you mention 10% or 20%. The only thing octane is preventing is detonation at that ragged edge.
What are we taking about here with the MDX HP? A few HP and possibly 2% or 3%?
The factory “tune” has the lowest grade of gas factored in . When speaking of tuning , think of your wipers going back and forth. The center is 0 .
-\0/+
The factory tune can compensate drastically to add fuel or pull fuel , as it could also change timing. When it gets outside of those \_/ parameters is when a check engine light comes on because the computer cannot compensate enough to stay happy. Which is why I reiterated that 87 is still acceptable and does NOT throw a Check Engine Light.

So you agree? the parameters that it uses to compensate, which it can and does do, cut power and efficiency for lower octane.

Pulling timing is inherently inefficient which the engine that is "0" tuned to run 91 must be doing to run 87.

For an engine that is tuned to run on 91, running at 87 is less efficient than the same engine tuned to run at 87 running 87. There is one specific timing that is the most efficient and that is a mechanical element of the engine.

 

[eurojap]

So, all engineers know that everything varies. There are no absolutes on the planet that anyone knows of. If 86 octane can damage the engine, buying 87 octane from some low budget station risks the octane being under 87. I fully understand that 87 is supposed to be the minimum but, refer to the first sentence.

I have been buying "premium" fuel for BMW, Mercedes, Acura, and even a VW for many years. Premium from one brand may be 91 octane while others 92, or 93. I really don't care. I just don't see how saving a few bucks on a tank of gas would be worth any level of damage risk. My personal experience says the higher octane indeed improves performance and mpg. Is it enough to justify the cost? Probably not. But, then again, I burn Benjis in my fireplace when I want a little extra heat (heh, heh).

The manual for the NA 3.5L states "Unleaded premium gasoline, pump octane number 91 or higher." There is no "recommended" although, I think it does say that on the fuel door. I have no doubt it would burn 87 with no appreciable deterioration in performance but, again, why? To save $4 a fill-up and prove what? It also says the engine may knock with lower octane. They mean lower than 91.

As always, to each their own but, I don't think choosing to run higher octane fuel, even if only recommended, is foolish. Only if you are burning $1 bills to heat your home does 87 octane in the MDX make sense to me.

 

[IanCH]

Gosh, bad gas is such a nightmare too. I put "93" in my S6 from the wrong station one time, had to replace all 10 spark plugs to get it running right again.

 

[eurojap]

Gosh, bad gas is such a nightmare too. I put "93" in my S6 from the wrong station one time, had to replace all 10 spark plugs to get it running right again.

That was some bad gas! Depending on the brand and location, it's like craft beers in a dive bar (I like dive bars BTW), it can sit in the lines for a long time before someone buys it.

 

[IanCH]

That was some bad gas! Depending on the brand and location, it's like craft beers in a dive bar (I like dive bars BTW), it can sit in the lines for a long time before someone buys it.

Tell me about it, most expensive fill up ever! The OEM plugs were $45 a piece and I bought them at a discount....

 

[TexasBlueAspec]

No where….? Highlighted “recommended.”
Highlighted top tier as in detergents not octane. Varies by supplier like Shell use to advertise. Also restated 87 is accepted and highlighted.
as for the tuning aspect again. The custom tunes look like // instead of \_/ where the window only allows a specific grade.

 

[Barry45RPM]

I get 26 mpg hwy, 19 in town on 87 octane, unimpressed with 91-93 octane, unlikely to go with ev unless compelled by feds

EV is NOT the future of the automobile. Short term it will be Hybrids then on to the next fuel (Synthetic or Hydrogen). We will never be able to produce enough electricity for all cars to be EV, nor can they traverse this vast country realistically. EVs are rich people toys.

 

[eurojap]

No where….? Highlighted “recommended.”

Agree Acura "recommends" 91 octane or higher and 87 isn't out of bounds. Yet, they warn 86 could damage the engine. To each their own. No shade here.

 

[TexasBlueAspec]

Edit: I hope this makes people laugh instead of being angry.