Not in the manual or the gas door.

When I had my 2G TL-S it said right on the door. Prem. Fuel only.

 

Definitely regular. There's no advantage to using premium.

 

Lord, not this shit again. Coach, stick to what you know: men tossing each others salads and touching each others balls.

 

Here's what I see each time I fill up. If found with past Acuras that putting in lower octane has mixed results, so I just stick with what they recommend.

 

I knew there was something on the gas door.

Now if it said Premium optional, different story.

 

 

I find it funny that Rick is advising people to use 87 when he's driving a leased RDX.

 

1st gen with K23A1 is running 8.8:1.. but consider you're under boost. Even a few PSI is magnified greatly under compression, play it safe. The 2nd gen is indeed 10.5, but that's not low by any standard. The engine will pull enough timing to try to keep knock at a minimum, but it's not just a performance issue, you're throwing unburnt fuel down the pipes.

Many of you could be losing mileage in the long run. The power difference won't be noticeable, so don't look at that as a marker. Worst is, the unburnt fuel is damaging the monoliths in your catalytic converters and could be fouling your oxygen sensor. I'm not here to sway anyone, but educate yourself. Don't pull those articles from edmunds or other sites that say otherwise, they're written by infants who aren't thinking of all the implications. Modern vehicle engine management has advanced a lot as well as engine / head design, but the rules still apply.. and there is good reason.

 

My wife accidentally put 87 in our RDX about 2 tank fulls ago. Gas mileage was reduced by about 10%. She was averaging 24-23mpg* before 87 and averaging 21mpg since. I think the mileage is down for a couple of tanks since she has been doing partial refills with premium. The butt dyno suggests that power is down too.

*She does about 70% city driving based on my calculations.

 

That's pretty significant..

 

I think so too. There could be unknown factors at play, but the only variable that changed in our minds was the octane.

 

Less efficient fuel burning is causing fuel economy to take a dump, not to mention the loss of power and rough idle in the long run.

 

Ditto!:rol leyes:
Originally Posted by Mr. Maker
This has to be, by far, the dumbest thing I've ever read. I have no faith in the future of mankind

 

Sorry kids...when the filler door states "Premium fuel required", I'll figure it's required. 36K miles and never once could I tell which fuel I had in the tank. Top Tier fuel...yes, 98% of the time. "Premium recommended" might just mean use a PREMIUM quality fuel...not a specific recommendation for octane. Otherwise, why not state "91 octane required". I've run many tanks of 93, many more tanks of 87 and a bunch of tanks of mixed 87, 89 and 93. Never in three years could I discern any difference in performance or mileage...never.

Again, if I drove fully loaded, lugged the engine or went to the mountains, I would step up the octane. This has been true since our '04 Volvo V70 with its 'recommended' mid-grade rating. If the vehicle REQUIRES a certain octane, I'll go with that. Recommended...not so much. With two vehicles, we've saved $6000 or more in fuel costs. I simply would NOT have done that if I EVER experienced a fuel related failure in any vehicle.

As to my leasing our RDX, I'm buying it in August unless I pay it off sooner. Are you saying fuel related problems won't show up in the first three years? Again, IF I read "91-93 octane fuel REQUIRED" , I would have played by the rules. I also would consider a different vehicle next time.

 

Actually, high altitude driving requires lower octane. "Normal" in Colorado is 85 (vs 87), mid range is 87 (vs89) and premium is 90 or 91. I tanked my BMW that "required" premium with 85 (all there was) and all was fine.

 

I've heard that but have never seen 85 in the Southeast mountains...our place is one of the highest @4200 ft. Little mountains, I reckon. I was actually considering the load on the engine(hard to maintain a high RPM rate with others in the vehicle) rather than the air density. Naturally, this applies more to climbing rather than descending.

 

It's my understanding top tier Premium fuels have higher levels of detergents which help minimize engine deposits, helping to maintain a specific level of fuel economy. This might explain manufacture's recommendations or requirements.
Sumoto

 

Actually, top tier gas requires the increased detergent additive in all grades of gas in order to be considered. Also (and as a shock to me when I looked recently) the retailers that offer "top tier" gas is significantly larger than back when this was first introduced back in the 90's. Chances are most of us are using Top Tier even though it's not a 'name brand" station. Just look at the list at their web site... Top Tier Gasoline

andy

 

Interesting to see Valero on the list. I don't believe it was on there when I checked just a few years ago. Pretty popular station here in central Texas. We have 'good' prices in Texas...saw 'premium' above $3 for the first time in months(airport station not known for low prices ). Been enjoying the sub-$2.50 prices for quite a while!

 

 

There has to be a way to shut this topic down. No good can come from it any more. It's been beaten beyond death. The body has decomposed and the bones have been pounded into a find powder.

Let's just leave at this. Do whatever you want to your car.

 

Care to elaborate?

 

 

Normal in C-Springs is 85. The BMW went up Pike's Peak without issues running that. 4200 is nearly sea level when compared to C-Springs or Pikes Peak (8000 and 14000)

 

Thanks for the question. I just got my new RDX so I'm curious too as 91 octane is now suggested but not required. After hearing the car guys on Car Talk say you could run regular instead of premium, I started experimenting between premium and regular in my 2006 Acural TL. I didn't see any real difference in performance or mileage and have had no engine issues or any engine repairs. My guess is I've been doing this for 50,000+ miles now. Not scientific so I'm interested in hearing more from Colorado Guy

 

Anyone do a comparison using ethanol free gas?

 

Well.. I look @ it a little differently.

I find myself upgrading the wine I drink as I think I'm worth it...

No reason my vehicle shouldn't get the same consideration...

 

Nearly impossible to find in central Texas...Oh, well.

 

A more applicable analogy would be to say you drink higher proof wine because you think you're worth it. Octane rating has very little to do with quality.

BTW, ...Valero has joined the Top Tier club. Their stores often 'look' cheaper; but I've never actually stopped in. They just opened a sparkly new store a couple of miles away. Unfortunately, they didn't have any serious grand opening prices on petrol.

 

How about an Ethanol versus No Ethanol debate? Or has that been beat to death also? Just asking. Seems that would be another great discussion?

 

Fixed it for you.

Beat to death too but is more academic because finding a station that sells "no ethanol added" gas is next to impossible in the US these days.

The more ethanol is added, the worse the gas mileage and the higher effective cost - but it is renewable energy.

 

Our dealer told us the same thing. We took delivery of our RDX on 2/29/16.

 

take a look:
http://www.nytimes.com/2016/09/23/au...ef=automobiles

 

http://www.nytimes.com/2016/09/23/au...ef=automobiles

 

 

I drive around 40-45k miles per year as an outside sales rep, so this is an ESSENTIAL question! I took delivery of my 2014 RDX base last Monday. Filled one tank with 91, then the subsequent 5 with regular (Citgo). I've noticed absolutely no difference in performance, feel, etc. No knocking, pinging.

Price difference here is ~+50 cents, or around 9 bucks a tank. Minimum 45 bucks per week...works out to around a $2000/year swing.

My 2 cents...

 

I decided to test this.... and filled up my 2017 RDX with regular ... it was completely empty so a full tank full of 87 octane reg.

To be quite frank, i have NOT seen any sort of performance loss...and although i have not exhausted the full tank yet, i am on track for obtaining the same mileage as I would have if filling up with premium.

 

Note that the Consumer Reports article never put their test cars on a dyno. The HP output will be less on regular compared with premium, but average drivers who rarely go past 4,000 rpm won't feel any difference. As for mpg, I've noticed a 1-2 mpg drop with regular.

 

I'm not sure what sort of comparison you're looking for. We drive between Wichita and Des Moines several times a year. It takes almost a full tank of gas to make the trip. Can't get ethanol free gas in Wichita, but can get it in Des Moines. I don't have the numbers handy, but the cost was almost exactly the same. Ethanol free gas was more expensive, but mileage increase made up for it. That's based on making 5 or 6 trips with consistent results. Wind does have a significant effect. I took those drives out of the samples. About the only advantage I can see to using alcohol is political.

 

2017 RDX base -

I used most of the first tank that was provided by the dealership - just filled up with Exxon 93 Octane - I only have 350 miles.

I plan to use 93 octane until I get over 1,000 miles - then try some midgrade 89 octane.

Regular 87 octane gas was $1.89 - midgrade 89 octane $2.08 and premium 93 was $2.55

Worth a shot - I am betting the midgrade will be fine.