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Is premium gas a must?

100K views 173 replies 46 participants last post by  nzone 
#1 ·
Ive seen conflicting information as to which kind of gas is required in the MDX. Ive seen both premium (91 octane) and regular unleaded... Which is it? And if premium, is it necessary to have the car run well? Just curious.
 
#2 ·
ebs0303 said:
Ive seen conflicting information as to which kind of gas is required in the MDX. Ive seen both premium (91 octane) and regular unleaded... Which is it? And if premium, is it necessary to have the car run well? Just curious.
Try doing a search, this topic has been discussed in great detail over the years. Welcome to the site.
 
#4 ·
My dealer recommended 89 octane and it has worked well for me now for over a year. No loss of power or performance and less expensive than premium 91 + octane.
 
#5 ·
There is more energy in lower octane fuels, so technically, 87 octane is more efficient than 92/91 octane.

All Acuras are reccomended to run on premium unleaded. You can run 87 and get away with it probably forever. If you live in a cool climate, you'll never notice a difference. But if the weather gets warm, you may notice a ping for a moment when you give it some throttle. But the knock sensor will pick it up and retard the timing (robbing horsepower) until it doesn't ping anymore. You may not notice this at all. We're talking maybe losing 10-15hp or so.

But you paid for an engine with 240 or whatever horsepower didn't you? Why potentialy cheat yourself out of some of that power? I'm a little more trained than the average driver, and I can tell the difference, and know when someone's got a tank of cheaper gas in there. Especially on the '01-02 engine. On a warm day with 87 octane, it's an absolute dog on the freeway on ramp.

If you find yourself never with a need to "floor it" with your MDX, then you probably don't need to bother with premium unleaded. As long as the knock sensor works...you won't be doing any damage to your engine.
 
#6 ·
Dear SuperTech


I have appreciated reading your recent posts, which I agree with.

I have posted extensively on the difference between using 87 vs. 91 octane.

Basically I said that unless you race your MDX or tow a trailer you do not need premium.

As you point out, it hot weather you might notice a ping, until the knock sensor kicks in.

What most do not know for example is that at 65 mph, most of your hp is used to overcome air resistance! But moreover, cruising uses less than 30% of your hp, so it really doesn't matter if you have 265 on tap or 10 to 15 less, as you are using only 85 hp!

However, aside from "pedal to the metal driving" or towing, I doubt you or anyone else can tell if the car is running on regular or premium.

Keep up the posts, they are informative and to the point.

JeffK
 
#7 ·
You might pick up a ping on a really hot day even under partial throttle. It may be to gas that may not even be 87 octane. I suspect several gas stations of having garbage gas in their tanks.
 
#8 ·
ebs0303 said:
Ive seen conflicting information as to which kind of gas is required in the MDX. Ive seen both premium (91 octane) and regular unleaded... Which is it? And if premium, is it necessary to have the car run well? Just curious.
Maybe premium is NOT necessary but 'peace of mind' is PRICELESS!!!
 
#9 ·
JeffK said:
Dear SuperTech


I have appreciated reading your recent posts, which I agree with.

I have posted extensively on the difference between using 87 vs. 91 octane.

Basically I said that unless you race your MDX or tow a trailer you do not need premium.

As you point out, it hot weather you might notice a ping, until the knock sensor kicks in.

What most do not know for example is that at 65 mph, most of your hp is used to overcome air resistance! But moreover, cruising uses less than 30% of your hp, so it really doesn't matter if you have 265 on tap or 10 to 15 less, as you are using only 85 hp!

However, aside from "pedal to the metal driving" or towing, I doubt you or anyone else can tell if the car is running on regular or premium.

Keep up the posts, they are informative and to the point.

JeffK
So what I would like to know is when using say 89 or 87 octane...What is consider hot weather? where I live...the temperature is around 69-80 degrees...so is this an ok temperature to use 87 or 89??? Because I have to tell you...paying $3.00 per gallon for 91 octane is really really HURTING ME since I drive a lot.
 
#10 ·
May I suggest the following:

Use regular. If there is no pinging, stay with it and enjoy the savings!

If you car pings, then go to medium grade. If it still pings, then go back to premium.


JeffK

PS: I find my MDX runs fine (as my other cars listed below) on regular up to 95 degrees!
 
#11 ·
I was always using 93 on my X until the cost is up to $2.80. I have been now using 89 for the past two months and no notice of less power or pings. I haven't gone to 87 yet and I don't think I will as we have 87, 89 and 93 on our pumps (most of them) here on Long Island.

So far so good, so I'll go with 89 from now on.
 
#12 ·
frainc said:
I was always using 93 on my X until the cost is up to $2.80. I have been now using 89 for the past two months and no notice of less power or pings. I haven't gone to 87 yet and I don't think I will as we have 87, 89 and 93 on our pumps (most of them) here on Long Island.

So far so good, so I'll go with 89 from now on.
Thanks for the feedback FRAINC. I will try to use 89.
 
#13 ·
Dear Frainc:

Why not put an extra 10 to 15 cents a gallon in your pocket and use or at least try 87 octane?

JeffK
 
#14 ·
My personal experience with my 2 other Acura's (94 and 95 legend's) proves me that the lower octane gas does NOT cause much differences.

I am still feeding the highest (93~94) to my MDX as it is being relatively new car to me (2004). However, sooner or later, I will start putting just regular grade gas.

I have been running 87 octane on my 94 legend, it has almost 200k with no problem.

As other's already saying, however, when I slam the gas pedal, I feel a slight difference in car acceleration performance, but no much differences in normal daily driving...
 
#15 ·
JeffK said:
Why not put an extra 10 to 15 cents a gallon in your pocket and use or at least try 87 octane?

JeffK
Bingo! It is NOT going to ping, and will affect your driving ONLY under wide-open-throttle conditions, which most of us seldom see. And I disagree with SuperTech on one thing -- my '01 is NOT a dog on an on-ramp with 87 (unless maybe you consider a second longer to get from 0 to 60 as being a dog.)
 
#16 ·
frostyra said:
my '01 is NOT a dog on an on-ramp with 87 (unless maybe you consider a second longer to get from 0 to 60 as being a dog.)
I've driven hundreds of MDXs of either the old '01-02 variety or the newer, higher output ones. Believe me when I say I can tell the difference.

And yes they were legitimate reasons to road test the MDX at wide open. I've had to chase down quite a few pinging complaints.

Adaptive transmission shifting also has a lot to do with what I perceive as a car acting like a dog on acceleration.
 
#17 ·
frostyra said:

Bingo! It is NOT going to ping, and will affect your driving ONLY under wide-open-throttle conditions, which most of us seldom see. And I disagree with SuperTech on one thing -- my '01 is NOT a dog on an on-ramp with 87 (unless maybe you consider a second longer to get from 0 to 60 as being a dog.)
Agreed, unless you always enter the freeway at WOT.
 
#18 ·
JeffK said:
Dear Frainc:

Why not put an extra 10 to 15 cents a gallon in your pocket and use or at least try 87 octane?

JeffK
Going from 93 to 89 was a big step for me as I always try to follow what's suppose to go into the car. But now with no problems with 89 I may try 87 if gas prices goes up even more than now. The difference between 87 and 89 is 10 cents here but over 20-25 cents from 89 to 93.

I may try it since other members here seem to have no problems with 87. My trips are 95% local around town so I really never push the X fast.
 
#19 ·
frainc said:
My trips are 95% local around town so I really never push the X fast.
It's not the "fast" that will be noticeable; but acceleration with your foot to the floor will take slightly longer. If you seldom do the "foot to the floor" thing, you won't notice much, if any, difference other than the $ savings.

Many of us think that the reason for Acura's recommendation for 91 or higher is two-fold: 1) "Luxury" cars should require premium fuel, and 2) the Fed's fuel mileage tests might show ever-so-slightly better mileage with 91 or higher.
 
#20 ·
Newspaper Article - Regular is OK

Here is a link to an article in this morning’s Washington Post entitled “Prices Fuel a Rebellion,” on using regular gas in cars that recommend or require premium gas.

http://www.washingtonpost.com/wp-dyn/content/article/2005/08/05/AR2005080501595.html

To quote one paragraph:
“Automotive experts say using regular gas in most vehicles does no damage and makes no discernible difference in performance. Cars made in the past 15 years have such highly refined computer controls that the engine will adjust to the grade of octane in the gasoline, even in cars sold as requiring premium gasoline. Some drivers -- in some cars under some driving conditions -- may notice a drop in horsepower, but for most people behind the wheel, it wouldn't be enough to notice, the experts say.”
 
#21 ·
Good article, I did change and now only put in 87 in my X and I really don't feel that I lost any power from 93. But then I just kind of drive normal so for me I'll save the 25-40 cents difference from 93 to 87. Yes, many gas station here on Long Island are charging 40 cents more for 93 than 87. Putting in 15 gal. is a $6 diffenance and that will add up during the year.

I still have alot of power when I need to get on the highway from the ramp.
 
#23 ·
frainc said:
I was always using 93 on my X until the cost is up to $2.80. I have been now using 89 for the past two months and no notice of less power or pings. I haven't gone to 87 yet and I don't think I will as we have 87, 89 and 93 on our pumps (most of them) here on Long Island.

So far so good, so I'll go with 89 from now on.
I don't know how true this is but my friend who owns a gas station says that of all the grades, 89 is the least consistent (meaning least reproducible) since the pump only mixes fuel grades from 87 and 91 to achieve 89 Anybody who's worked at a gas station can verify this?
 
#24 ·
loa3 said:
SuperTech -- Can you explain to us why the Pilot calls for regular gas (unless towing) and the MDX calls for premium. Same engine, same compression ratio -- what makes the difference?
That's a good question. :confused: The MDX engine makes 10hp more at 200rpm higher, so if I had to guess I would say the MDX is set up with a little more aggressive timing, which would be more prone to knock--hence the requirement for premium fuel.
 
#25 ·
Re: Newspaper Article - Regular is OK

042005 said:
To quote one paragraph:
“Automotive experts say using regular gas in most vehicles does no damage and makes no discernible difference in performance. Cars made in the past 15 years have such highly refined computer controls that the engine will adjust to the grade of octane in the gasoline, even in cars sold as requiring premium gasoline. Some drivers -- in some cars under some driving conditions -- may notice a drop in horsepower, but for most people behind the wheel, it wouldn't be enough to notice, the experts say.”
Man, that's funny! :2: It starts off saying "makes no discernible difference" and ends with "may notice a drop in horsepower". Which is it, Sherlock? Such "experts" amaze me :)
 
#26 ·
frostyra said:
2) the Fed's fuel mileage tests might show ever-so-slightly better mileage with 91 or higher.
Twice, I tested almost a full tank of 89 vs 93. Keep in mind, that I drive almost the same route everyday. And with 89 I got an average of 4 mpg less than with 91/93. I'd say that's more than a ever so slight difference!

I've said this before - MDX, and most other cars recommending premium, will run absolutely fine on 87 (maybe even Kerosene :)) but its ingenous to claim that it does not affect hp and mileage to a noticeable degree.
 
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