mav238

Over here in Vancouver, I can only really think of two gas brands i would fill up in the RDX.

both of them being Top-tier gaolines...

Shell 91 V-power
Chevron 92 techron

Have used the above gasolines in my wife's current TSX, and they have been great.

used ESSO before, and not impressed with quality and performance gotten from it... didn't seem to keep car engine running smoothly...

omgacuralol

Chevron 92

rpeete

BP/Amoco 91

PERDY

wawa premium $3.01 a gallon

RedGSX

Chevron 93

ozwaldo

Conoco 93 in Houston

Fishbulb

Usually PetroCan 89. Works well.

oasis3582

Mobil 93 Octane

If I wanted to be really cool, I would go for Sunoco 94 octane

turboted

Mirastar (Walmart) 87 (currently $3.15 a gallon in CA). I was advised by my Acura dealer that here in California, due to additives in gas, 87 regular in California is the same as premium in the other 49 states. Have never had any issues (other then higher price) with running regular in CA, in my RDX.

mav238

I hate to say this... but I don't think you understand how engines work... the additives in the gasoline has nothing to do with the potential power it can help the engine produce. The addtives in the gasoline keeps the engine clean of deposits, but if you put 87 gas in the engine, you will most definitely cause the engine to adjust it's ignition timing, and thus it's performance will be hit. Over the long run, if you like to use the turbo, the engine will knock or ping... especially if you do tow something...

Read your manual, don't just listen to your salesperson... it clearly says what I indicated above... use 87 gas only if you don't have a choice, but if you do, premium 91 is a minimum for longevity and proper performance of the engine.

porsherules911

+1

SolidState

+1 and only.

SolidState

That's odd, didn't know additives where the same as octane. Also, I thought the Octane count was regulated to be as stated or better.

laputa

Chevron 94 FOR SURE

mbjude

Mobil/Exxon 93 Octane.

jinx

shell V-Power

oasis3582

Beat me to it. Tried to say this in another thread, but it was duly ignored.

And to turboted...if an extra $0.20/gal is a dealbreaker for you, why did you buy an Acura?

bibby

Chevron 94 in Vancouver. But looking at the price, may have to go one step down to Chevron 92!

Madison3

Not picky on brand, but usually Shell.

turboted

You only have to do a simple google search on Regular 87 vs, Premium 91 fuel to get all the real facts. You pis*ing your dollars down the toilet if you think Premium price fuel is better for your RDX. here is information from just one of the articles...

"REGULAR VERSUS PREMIUM GASOLINE
Regular Gasoline Has As Much Merit As Premium Gasoline
"Put a tiger in your tank," says a classic advertising tagline. In today's motoring world, what kind of fuel grade will have the power to place a beast in your gas tank?

The answer, according to experts who study fuel efficiency in detail, is both regular and premium gasoline. And it would be a waste of money to favor premium over regular, especially in these times when gasoline prices are high, according to the experts.

Virtually nothing is gained by filling up with a premium or more expensive grade of fuel than the vehicle manufacturer has recommended, the experts say. And many of the same experts explain that drivers may not lose much performance from their cars by using a lower grade of fuel than recommended by the car manufacturer.

There is little difference in energy content of regular versus premium gasoline. They both contain about 111,400 British Thermal Units of energy per gallon.

The price difference, however, between the fuel grades is anywhere from 20 cents to 40 cents, depending on where you live in the United States. The experts' consensus goes against the long-held belief by thousand of drivers who fill up with premium only, or on every third or fourth trip to the pump. The idea is to fill up with premium every so often to clean out the engines or rev up the performance of older engines.

But according to the experts, this practice is like tossing quarters in a wishing well, since most engines are designed to operate on relatively low-octane regular unleaded gasoline.

Octane is defined as a fuel's resistance to knocking. There is no benefit if the octane is higher than what the engine needs. Engine knock occurs when fuel in a combustion chamber ignites before it should. This disrupts the engine's operation. But electronic knock sensors are now common and have nearly eliminated engine disruption.

The American Petroleum Institute says if you find that your car runs fine on a lower grade, there is no sense switching to premium. The Institute recommends following manufacturer's recommendation, but even those manufacturers say that it is more of a suggestion than a command."

So far after 4 fill up's a on regular vs. 2 fill up's on premium, I can find no difference in performace on my RDX. It's your choice, if you don't mind giving the oil companies more of your hard earned money, go ahaed a pay extra for premium. I have a very good relationship with my Accura dealer and they have not done me wrong with the recommendation to use regular.

F.Rizzo

It's not about the BTU's Einstein !!

It's about the resistance to knocking! Higher octane fuel burns slower and allows the combustion to complete without "pre-ignition"


You are really blowing it by putting low grade fuel in the car. You can find plenty of cheapskates on the web to backup your theory on 87 octane, but the fuel door clearly states "Premium Fuel Only". Read the owners manual.

Me thinks you should have bought a Mitsubishi.....

mav238

Well, it seems that your mind is pretty much set on using 87 regular gas. That's fine... it's your RDX anyway...

But to just make sure others who is a little unclear about this issue of octane vs knocking... you indicated that the API recommends that drivers put the kind of gas into their vehicles as recommended by the car manufacturer... well.... turtoted... check your car manual again... it clearly says the Acura RDX engine was designed to use premium gas... and it also says use 87 gas only if the 91 octance gas is not available... meaning, if you are stuck somewhere in Timbuctu... and the highest grade available is 87, use it to get out of the emergency situation...and the manual did say... make sure you put back 91 gas back in again...

You say the performance is not affected... try driving it up a hill on load...

This is not the first turbocharged car I have driven... SAABs are known turbocharged cars... I have not driven one that didn't say use premium gas.... why... because turbocharged engines use highly compressed air /fuel mixture... meaning premium fuel is required to extract the full potential... your car is tuned to do that using premium fuel... so if you use regular gas... it retards the ignition timing (hence the "anti-knock" sensor")... But there is only so much the ignition can be retarded... under full load... no matter if you have knock sensors... your engine will "ping" and "knock"... especially after some time which the car has beem used... "pinging" and "knocking" is not good your engine...

Trust me... if I know putting regular gas into my engine is fine... I would... But if you trust me... trust at least those experts in the API, use the right gas for your engine AS RECOMMENDED BY YOUR CAR MANUFACTURER.


Anyway, it is still your RDX...

It is not about instincts... it is about knowing the facts of how engines work...

sasair

According to that article, you should be using premium. Most of the entire article is based on using premium gas in an engine designed for regular gas which doesn't apply to Acura engines. Just because the engine computer can compensate for the lower octane, doesn't mean it is running the same as with premium.

loulinjai

the article is right. I am no fuel expert, but I am a chemical engineer and I have done courses regarding fuel requirements, four stroke motors, otto engine cycle etc.

"Virtually nothing is gained by filling up with a premium or more expensive grade of fuel than the vehicle manufacturer has recommended, the experts say. And many of the same experts explain that drivers may not lose much performance from their cars by using a lower grade of fuel than recommended by the car manufacturer."

I totally agree. except K23A has a recommended fuel of 91 octane from the manufacture. manufactures dont recommend this just to screw you over. According to Acura specs, peak boost pressure is approximately 13.5psi. Assuming ideal atmosphere pressure. That means the pressure of the combustion chamber BEFORE any compression is done is about 28PSIA. Most motors built are designed for 87 octane fuel without any knocking problems, but I would strongly disagree this is the case for the RDX. The owner manuals states regular fuel may be used on a temporary basis, but long term use may affect engine reliability and performance. I totally agree the energy content of regular and premium fuel is similar, however, they will spontaneously ignite at different heat and temperatures (knocking). In this case, it's not how much energy is given off by the fuel, but how much useful energy can be extracted rapid expansion of hot gases from combustion.
As for 87 octane in CA equal 91 octane everywhere? that is complete BS to me. All octane ratings in US and Canada are based on (R+M)/2 ratings, the average of research and motor octane ratings. I also agree as stated in the above post that "there is no benefit than what the engine needs". Most members on here are passionate about their machines, so i'm not surprised by the responses given. You purchased the vehicle and you can do whatever you want with it, for all we care, you can run it on cow poop. But you might run into engine and warranty problems in the long run with complex turbo motors, and honda/acura do have scan tools that can determine prolonged use of certain fuels, and they have the right to void warranty on repairs since wrong fuels can be considered misuse.

Sauceman did a great experiment using different fuels for his TSX, and the mileage he got, you can search for it on the TSX forum.
http://auto.howstuffworks.com/question90.htm
this is a great site that you can get lots of info from. Other than retard timing, One of the ways a motor compensate for knocking is to inject more fuel, using the heat of vaporization to adsorb heat to cool cylinder temperatures. So basically, although your gas is cheaper, you are injecting more of it than needed. Hope this helps. Remember, a few dimes per gallon differences may not offset the cost of expensive engine components if they are damaged from knocking

porsherules911

+1... If the engine wasn't turbocharged, then you would have a stronger case for using regular but how could you not give your turbocharged engine the right fuel? Using regular fuel will be fine short term but whats the point in saving some pocket change now in place of your vehicle's reliability? Don't be surprised when the car starts to have mechanical issues in the months and years to come.

ex2k4

I won't even write my own opinion about what this guy thinks. But what he quoted should have answered his own question.

It doesn't make the car/engine perform better bc you put 100000 octane in 87 recommended car. But you do need to put what is required by the manufacturer for the gas to burn at its pace. You may not see the changes today, but you will in the long run by using what is recommended by the Manufacturer. And whoever told you cali's 87 is same as other states 93......................... for believing that? no comment..

Motortrend and some other magazine actually did the testing sometimes last year on this. The m3 lost 5-6 ponies when 87 octane was used where there was NO gain, but actually lower gas milege from 93 octane on a camry(?) which required 87 octane.

OC-RDX

Anyone know of any stations in LA/Orange County CA that sells higher than 91 octane?

FYI, I've bought 91 from all the major stations & independents & haven't noticed any difference in performance. I buy whatever 91 is cheapest. Can anyone convince me why I should favor one brand over the other for my RDX?

mav238

You are right... as long as you are buying the gasoline with minimum avg. octane rating of 91, you will not see much of a difference in performance at all. But some gasoline from certains brands or stations are more "dirty" than others, namely in the refining part of it and also the concentration of cleaning agents. Reputable brands such as Shell and Chevron have good standards on the refined gasoline, plus they have added detergents in it to a level of being Top-Tier.

The difference you see with buying certain brands over the other, is in the long run. I have experienced using Shell V-power and Chevron premium, they have been great in keeping my TSX running like new. On the other hand, in my previous 2001 BMW 330i, where I was feeding it ESSO supreme, after 2 years, I noticed that it's performance and gas consumption had degraded significantly. I used Chevron Techron concentrate and cleaned it out, started to use chevron exclusively; following that, performance went back up, but of course only reached 70% of what it used to be.

You can save a few cents now, by using the cheapest available, non-major brand, and possibly pay for it in the next couple of years. For that few cents difference per gallon, I would suggest staying with reputable brands, especially Top-tier ones.

oasis3582

Keep a check on your mileage. Running the same route to work every day, I got 2 less mpg with Marathon 93 than I did with Mobil 93. Performance-wise, the difference should be nil.

ozwaldo

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QuikTrip
Chevron
Conoco
Phillips
76
Shell
Entec Stations
MFA Oil Company
Kwik Trip/Kwik Star
The Somerset Refinery, Inc.
Chevron-Canada
Aloha Petroleum
Tri-Par Oil Company
Shell-Canada
Texaco
Petro-Canada
Sunoco-Canada

ex2k4

so No BP? isn't BP same as Texaco? or was it amoco.....

I'm surprised to see QT over BP in that list.

Tonia

Mostly I use Premium from QuikTrip (QT). Honestly, I don't recall the exact octane. And whenever I'm at Costco, I'll usually fill up there.

Tonia

BP = Amoco

visuelz

The Acura website says the RDX takes, "Premium unleaded 91 octane"

mav238

I would really refrain using gas at Costco.

I know the usual saying: "all gas are the same"... honestly, years ago, I thought of that too... filled up at Costco, and our local supermarket chain "Superstore". Man... it sure hurt the general functioning of the car... If you want to enjoy the car for years to come, with little to no issue... use Top-tier gasolines and not "unknown" brands...

brizey

Acura recommends 91 octane. Why on Earth would you not use it? The computer will pull timing, and maybe even lower boost if you use 87. Will it hurt your RDX? Probably not. But I really doubt that there is no performance hit. "Feeling" the difference is not possible. Do you have logging software to track the inigition advance? Fuel injector duty cycle? Does your RDX have a wideband oxygen sensor or a EGT gauge? If not, then I would recommend using the recommended grade of gasoline for day to day operation, which is 91 octane from what I understand.

I use Chevron 93 for both by stock Forester XT and my WRX (which is aftermarket tuned for 93 octane).

mav238

Basically turboted just wants to use the cheapest and lowest octane gas available, based on the "well established" folklore of "not needing to use gas octane higher than 87 if performance increase is not felt". Hey, Turboted would not be the only one believing that... years ago... I used to think that too!!!


I ran my previous 2003 SAAB 9-3 sports sedan turbo on 87 gas... did i notice a performance difference? You bet... on driving at 50 km/h on city back lane, couldn't tell the difference, but when I loaded the turbo with gas pedal, it was like asking a chihuahua to pull a cart meant for a bull... the engine "ping" ... not a nice sound at all... my gas consumption degraded as well...

I mean if you lease the vehicle, or not really caring too much about your car as a hobby, besides just being a commuter car..., then i say, go ahead and put anything you want in it, as long as it keeps the car running... At the end of the day, the car will be returned as a lease vehicle anyway...

When I traded my SAAB in for the RDX, i had a 5-6 weeks wait for the RDX, I ran the SAAB on 87 octane for those 5-6 weeks... didn't want to put more money into a car I am trading in...

But if one would buy a luxury end CUV like the RDX, why wouldn't you want to put in the right gasoline type for it? If RDX was spec'd to run on 87 octane, sure, I would be stupid to put anything more than that in it (because as the article Turboted put out, indicate correctly that it would be a waste of money to do that).

Boggles my mind...

visuelz

I'm surprise why he didn't just get an CRV...

Boon

Damn, my family's been using Esso supreme for years (most for the extra Aeroplan points). Anyone else notice a performance loss with Esso gas?

Fishbulb

I'm with you, TurboT, but I've done some testing with all levels of octane, over 30K miles, and found that with 87 octane, mileage suffers to override any savings at the pump.

On the other hand, mid-grade (89 octane) has netted me mileage just as good as 91+, and performance is identical also. Suggest you give that a shot.