vichardy

I know this has been hashed over but I have a question:

So when I picked up my '22 MDX on Monday, the salesman said use regular as that's what they fill their cars up with. My local dealer (bought it out of state due to selection) salesman said high test only, that the shop told him you'll get long term carbon build-up if you don't.

Then I went to the service department and one of the advisors said that Acura recommends high octane, but to put in what's on the fuel door, which turns out to say 87 - 91.

Here's what the manual says:

Q. Unleaded gasoline with a Pump Octane Number (PON) of 91 or higher is recommended. Is it possible to use unleaded gasoline with a Pump Octane Number (PON) of 87 or lower on this vehicle?
A. Use of a lower octane gasoline can cause occasional metallic knocking noise in the engine and will result in decreased engine performance. Use of a gasoline with a pump octane less than 87 can lead to engine damage.

So 91 or higher. And when I did a quick google on carbon build-up, the first link said that higher octane leads to carbon build up, so should 92 or 93 be avoided?

High-test is usually 20 to 40 cents higher; at my local Costco it's now 46 cents higher so a full tank will be about $5 more. Choices.

I'm probably over-thinking this and given that I just paid $60K for a nice vehicle should just go with 91. But I guess my question is if people feel that 87 would really be bad for the car over time. it seems to have run fine on the initial tank of 87.

Also, do people see a noticable performance increase or better mileage?

vichardy

it might be fun to do a simple survey that asks which octane people use, 87, 89, 91, 93. Anybody know how to do that?

tamber877

I use 89 most of the time. If I have a good amount fuel points I'll go with 91

bugsnest

i thought I was the only one who agonized over this, glad to find a friend 😄

My research on this led me to this conclusion that I follow -

1) Check what the manufacturer “requires” versus “recommends”. The latter just means that a higher octane would give you “optimum” performance but a lower grade would do just fine.

2) The 22 MDX will work fine with 87 and that’s what I intend to put. I understand I may miss out on some aspects of performance … so I may not hit the 0-60 numbers as Acura claims because of the lower grade fuel.

But honestly we are getting this car for my wife to travel back and forth from work (mix city/highway driving) and running errands and transporting kids. If she’s flooring the vehicle doing this, then we have a problem on our hands lol!!

I still use 93 grade on my 2018 TLX because I drive that thing like I stole it. So if an extra few bucks ensures I get to enjoy that car longer, the way I drive it, then I can live with that.

Hope this helps.

mrgold35

My 06 TSX, 08 RDX, and 11 MDX required +91 Octane. I like Acura move to give owner's more flexibility to pick between different octane level to dial in the level of performance and budget that works best for their driving style and environment (with zero risk of damage to the powertrain). I go with 91-93 Octane for my 18 RLX hybrid and 19 MDX hybrid with Sam's or Costco gas. I find the price of 91-93 there is very close to the same price as 87 Octane at the main corner store gas stations. Other than ECU/AT programming to optimize performance at 87 or 91 octane, I don't know if there is a physical difference between the 3.5L+10AT for the Honda Odyssey compared to the +22 MDX other than peak hp/tq on different fuel octane levels?