How many of you RL owners are using premium gasoline? Prices in S Cal remain at $4.00/gal for premium or higher. I adhere to factory recommendations and run premium - however my son purchased an 06 RL new - put close to 300,000 miles on it - never had a problem with the car - and NEVER ran premium. 80% of driving was done at freeway speeds.

 

we've done the math over and over again.

the $ you save at the pump by pumping regular fuel is negated by poor fuel economy because the computer in the car pulls timing.

do what you please, tho.

 

You gotta pay to play. If you want cheap reliability, buy an Accord.

You only have to use 91 octane.

 

Where does anyone find 91 octane? All I have ever seen is 87, 89, 93. Do people mix half 89 and 93?

 

Some states dont offer 93 octane.
Instead, they offer 91 octane.

 

Texas doesn't offer 91, but MS does.

You can mix 93 and 89 if you feel like pinching the pennies, but I'm sure we could point out 100 other ways to save a dime or two.

EDIT: Looks like a lot of West Coast states and mountain states offer it.

 

 

Here in MD/DC/VA we have 91 and 93 octane at certain stations. Otherwise its only 93

 

And I used to think it was bad when this topic came up on the Prelude forums back in the day.

 

Not that desperate lol

I was just curious since I've never seen it

 

I usually run 89. We have 93 here but when I worked for an Acura dealer, we filled them all with 89, with the logic being that a lot of states can only get max 91 and that there is no benefit wasting the money for 93. There is no scientific research to backup what I do, it's just the habit I got into and I've had no issues with it.

 

The RL has an internal knock (ping) sensor that will detect early detonation from low octane fuel. If the sensor detects knock, it will retard the engine timing to compensate and avoid damage. This will affect performance and ultimately engine efficiency (mpg). What you gain at the pump, you lose on the road, and you run the car in a modified "limp" mode.

 

I'm going to say this once and then I'm out...If the difference in cost from regular to premium gas is that big of a dent in your wallet, you probably shouldn't be driving an Acura RL....or any Acura for that matter. A Toyota Corolla is a much less expensive car to own, runs on regular unleaded and still gets you from point A to point B.

 

You just reinforced most peoples lack of trust for the dealer.

 

exactly, why buy a performance/luxury car if you are going to ride around in limp mode and then bitch when it throws codes at 100k?

 

Fawking .

Shit, you could even own a TL or TSX, and get 40-50% MPG improvements.

 

Premium is 20 cents more per gallon around here, so 20 cents X15 gallons is 3$. You're gonna complain about 3$??? I'm pretty sure your lunch is more than that, just saying... That's 156$ a year. Assuming you own your car for 5 years, that's an extra 780$. Now, how much did you pay for your car again?

 

I have never used less then 93 in my rl and even when I had my cls

 

Been over this territory, son. Asked the question myself. Poster "Costco" put me in my place with this well-considered reply:


"YES it can damage your car. More specifically, your EVAP system and/or your catalytic converters. On some cars using low-octane fuel will set a fault code and sometimes it means the charcoal canister has taken a crap.

"And guess what, because the dealer found out that your knock sensor wasn't faulty, they can probably track it down to low-octane fuel thanks in part to misfires in every cylinder and deny your warranty claim. Ouch. Now your car probably won't pass smog either, if you have it in your state.

"Even though you didn't ask.... no, it is not smart to risk spending hundreds (probably a few hundred on the cat alone) on a new cat(s) or charcoal canister in the pursuit of saving one or two bucks each fillup. Roll the dice if you wish. After all, the guys that specified 91/93 octane for your RL are only mechanical engineers, they don't know jack squat about what's best for your car, even though they're the ones who designed the engine..... you have nothing to worry about!"

There are many contemporary cars that "recommend premium fuel for maximum performance" but aren't harmed by regular -- they just retard the timing and run a little slower but without damage. However, the RL apparently is not one of them.

 

I've always ran 93 in all my cars and especially my sport bike. For my 55k dollar acura RL, I will continue to run 93, I always do the best of everything for my vehicles, even if the car doesn't need high octane

 

The fact is is that no manufacture is allowed to sell a car in the U.S. and have it not be able to run on 87 octane. You can't blow your engine and take it back to the dealer and them say, "Well, you were only supposed to run it on Premium octane." I haven't had a single issue running many many tank fulls of 89 octane in my car. Can I afford the extra couple bucks? Of course. However, unless somebody posts some legitimate dyno results of testing 89 to 93 back to back, I personally don't ride on this high horse of needing 93 octane because somehow it is better simply because it is more expensive. It's not a higher quality, only a higher octane rating. There have been more than enough tests done to show that you actually get more power using the octane that your engine was designed to use and getting less power if you use a higher octane. It's not an air-cooled engine running on the brink of detonation or some super high compression ratio, it's simply a Honda V6. If it makes you feel better running 93, go ahead. Your money. I'm just saying that I don't feel it's necessary.

 

^what do you use? 87?
have you checked mpg in 87 vs 89 vs 91 vs 93?
I bet you are not saving any money

 

I was running steady highway all summer last year, filling up 3 times a week. I tried 93 vs 89 a couple times, it didn't make any difference. Ran the same and I got around 22 mpg average. Honest;y, I wanted it to perform better on 93 so I could justify the cost and maybe gain a couple extra hp, but it just didn't happen.

 

My dad is a mechanic and he said I can run lower gas but I have to double gasket the head on the engine has anyone heard of this before? His been a mechanic since the army and owned a shop when we used to Live in Europe

 

By enlarging combustion chamber volume you get lower compression ratio and can run low octane gas.

It's a common technic.

 

a

 

The manual says 91 octane. I don't think 89 is so far off that you will see drastic differences. However, I do believe 87 is. In any case, the butt dyno and road tested mpg are not even close to good scientific evidence. When the engineer tells you that they designed a system a certain way, that doesn't mean it won't work outside of typical conditions. In fact, it will usually work well beyond those. However, the performance and the life cycle of the design are optimized by those conditions.

The only reason I ever filled up with 93 wasn't because I "needed" 93. It was because TX doesn't offer 91.

 

Thanks for added on tidbit This topic crops up on average once a month on the Toyota boards, but it's a slightly different discussion there.


On the Camry boards, we're dealing with the ES300, the Camry and the Avalon, which have IDENTICAL powertrains... Same head design, cams, block, crank, pistons, tune and power ratings, yet the Lexus and Avy's required premium, while the Camrys with the same V6 only recommended premium in the manual. There, I would agree, 87 can stick. Here, it's a little different seeing as the J35A8 is different in some key points than other J35's... I wouldn't venture too far below 91...

 

And if it makes you feel better running 87 in a car whose manufacturer clearly states it requires 91-93, go ahead. Your car. I'm just saying that I don't feel it's advisable.

 

In states that have 93 instead of 91. What are the other 2 octanes offered?
In CA, we have 87, 89, and 91. The 89 is mixed by the pump from the 87 and 91

 

I'm so use to using premium fuel that I add to my gas container for use in my snowblower and lawnmower lol. I use Shell 91 since it also is one of the top-tier gasoline retailers in my area. I've also used Sunoco 93 despite it not being a top-tier retailer and I've had no issues with it.

 

87, 89, 93 in TX.

 

I think I'm going to give 89 a try. I fill up at least twice a week, spending well over $120 a week, here in NYC/CT. I'm going to pay close attention to my mpg and see how much of a difference it gives me.

Thanks for all the input and info boys.

 

Must be all those old pick ups that still require high octane

 

I have a question I've been kicking around in my head for a few years now.

Don't flame me. I fully understand the concept of octane, compression ratio, etc. But here is my question:

Is the pressure in the cylinders the same regardless of load, or is it variable according to the throttle?

I would think that any throttle position less than WOT would mean that the cylinders aren't filling up all the way with a full charge of air/fuel.

If the engine requires premium octane in order for the fuel/air mixture to not spontaneously detonate when the cylinder pressure is at full design specs, the pressure must necessarily be less if the fuel/air mixture is decreased. Lower pressure means lower octane needed to resist detonation.

So the logical conclusion if all of this holds true is that if the car never sees full hard acceleration, it may never need higher octane gas.

Could somebody tell me why this would not be true? I could be fundamentally flawed on my understanding of how throttles work.


PS: I always use what the manual calls for. But this is a thought experiment.

 

^^^ That is a great question and I'm interested in seeing the responses... *popcorn*