Ok, do not flame me for this. I am not a cheap, but I wanted to see if and what would really happen if I use regular 87 Octane. Since I am still under warranty and wanted to help other 3rd Gen TLers to finally put this topic to the test.

I started using ARCO 87 octane on September 1st and monitored the mileage, performance, engine noise, and practically maintained my normal Driving condition. I also had the help of my friend who is a UPS mechanic for over ten years to monitor the tuning of the engine.

The result:

Average Miles per gallon stayed the same at 26.7 miles per gallon.

No change in performance, in fact the Bay Area Group including the Distinctiv_Tuning was at hand for the twisties.

https://acurazine.com/forums/acurazine-clubs-meets-15/last-bay-area-meet-2005-october-15-10am-319421/


After the two months, I brought my car for a complete diagnostics at Serramonte Acura. for the 30K service. I also told them that I wanted to see if there is any change in the performance and tuning. After half a day of waiting, my car was ready and the service advisor told me that the car has no issues for the normal 30K service. The Computer Diagnostics were allnormal, they then asked me what were my expectation? I told them that I was expecting change is performance since I was using regular gas. They then recommended to switch back to premium gas. LOL after telling me that my car was fine.

Ok....after the two month experiment, I am back to using Premium 91 Octane Chevron w/ Techron. JUST MY PREFERENCE

I've proven to myself that there really is no problem using regular gas and this was also confimed by Dr. Bill Wattenberg a worl renowned scientist and a Nobel Prize winner. http://www.kgoam810.com/viewentry.as...=PERSONALITIES

Here is his take to Gasoline usage: http://www.kgoam810.com/viewentry.as...=PERSONALITIES

Ok..this is in no way saying that the use of 87 Octane is ok..I just wanted to see for myself. Use 87 octane at your own risk (like I did). My car did not have Knocking and performance was the same.

 

I must question your definition of "performance". You mentioned twisties, which has virtually nothing to do with a marginal loss of power due to the lower grade octane. And I don't understand what you expected of a dealership testing for a change in performance and tuning. Dealerships aren't equipped to measure the amount of power output of individual vehicles. They can hook up the diagonistics scanner and check the ignition timing, but since the computer is compensating, I'm sure it came back normal. If you ran lower octane like 83, outside the compensable parameters of the computer, then it would've raised a red flag. And obviously it isn't knocking, because the computer is compensating.

Run 91 for a couple of more tanks, then dyno your car for a base line. Then switch to 87 for a few tanks, and dyno again. That's the only way to tell if there has been "a difference in performance".

.02

 

Hmmm....you are right "Performance" change can be seen on Dyno for baseline.

My way of testing performance is the Avg Mileage per gallon which has stayed the same. Plus i do not use all of 270 hp, so for me there is no change. At least I know that for what i paid for the car ($35K+) I am glad the computer is working to compensate.

I would have used 83 octane but there is no gas station in the Bay Area that sells that. As i told you this was my experiment. Take it for what it is....OK?

 

no surprise there. Using lower octane basically nets you a little bit less performance due to a slight retard of the timing.

 

Yeah I know..I was actually expecting some knocking but never heard any..

 

Of course, I know it was just an experiment, and I do take it for what it is. It's just in my nature to question.

Thanks for the information, though. Not many people have actually done experiments like this; at the least, you've provided us with the fact that using lower grade octane wouldn't affect gas mileage much (provided that your driving style wasn't modified at all, because you are aware that you're doing this experiment.... there I go questioning again.. ).

 

Not changed the driving at all...my route is the same and I am always late for work...If anything else, I was actually liking the use of regular since it was gentle to my wallet.

I am aware of the diff parameters and that experiments has to be under a controlled environment.

Once again...this is my experiment and my feedback is for informational purposes. This is to provide info to other 3rd Gen TL'ers and not in anyway trying to persuade anybody to do the same thing. I just thought that since this is ACURAZine and that we all share info that it is ok to provide feedback to what I believe was sharing the result of "MY EXPERIMENT".

If you were to provide the same experience, I would be very interested. But then again this is me...and you are you....

 

Hhhmmmmm....why dont you do this experiment and provide us with your results....at least you would be helping the ACURAzine Community.

Dont forget that you have to do this under controlled environment.

 

Eh, the V-AFC 2 has been tuned and set up. I don't want to risk anything.

 

Oh...you mean the VTEC-AFC II Controller that adjusts the point at which the engine switches from the Lo to Hi cam during acceleration, as well as when the engine switches from the Hi to Lo cam during deceleration....By the way is there any change in "Performance". I sure would like to know since I am thinking of getting the Apex1 V-AFC-II.

 

Yeah, but that's not its main function. Its primary function is to adjust fuel delivery.

My car is tuned to a specific AFR based on 93 octane. Changing to 87 octane while on these settings could have some bad results. It works.

 

I wouldn't want to experiment with my car just to put a topic to rest. Besides, if you really want to do a test, use 89 as well and as one poster said, dyno before and after.

I was watching one of those spike tv shows on a saturday and they took out the stock oil from an engine and replaced it with synthetic. They were able to prove that there was less heat from using a surperior product and there was more torque since they did a dyno run before and after.

 

Interesting, but I'm still not going to use regular gas in my TL. It was designed for premium and that's what I'll use. It is a $35,000 car after all so I'm not going to cheap out to save a few pennies on regular gas. If it were an old "beater" car, I wouldn't care but not with a new Acura. If you can't afford the premium fuel, you probably shouldn't have bought the car in the first place...get an Accord or Camry that use regular gas.

Good experiment though, and thanks for posting your results.

 

No Flame here - Thanks

 

if you weren't around to see this back then, here it is again. at least the BMW M3 is still the current model (barely). there is some dyno testings in it.

http://www.caranddriver.com/article....rticle_id=3604

interesting quote for people who think permium is always batter even when the compression ratio doesn't require so.

"The Accord took a tiny step backward in power (minus 2.6 percent) and performance (minus 1.5 percent) on premium fuel"

hope this helps.

 

Well, if you are drive on the freeway with little traffic, high octane gas is just fine with the TL. However, if you sit in the traffic most of the time, high performance gas won't make much of the difference. Both premium gas and regular gas are burned during the idle with 0 mpg while you sit in traffic. However, the price difference between premium gas and regular is about 0.20.
Say 15 gallons tank, 0.20 * 15 = 3.00 (skip the Starbucks coffee, you will be just fine if you want premium gas).

 

~$3 a cup x 2 cups/day x 5 working days = ~30 /week. if you skip all starbucks all together. ur like riding on free gas all the time. lol.

 

Just out of curiosity, did you a get a full tank of gas when you drove off your new 35K TL off the dealership??? Did you know that you were driving on 87 octane gas for the first and most precious miles of your brand new Acura TL engine. The insteresting fact here is that the people that tell you to put 93 octane gas on your engine are fueling your vehicle with cheap 87 octane gas.
I am going to sound like the girl from the movie MY COUSING VINNIE, but my uncles are mechanics and my cousins are mechanics working at dealerships of different car brands, and they all agree that dealerships buy the cheapest gas to put in the vehicles. Just my

 

This is true.. when I bought my TL the sales guy told me he was going to fill it up with "the good stuff" before I got delivery. Somehow it just didn't sit right and sure enough I found out later on that the dealership only uses regular gas. So yeah... almost everyone has broken in their cars on good old regular!

 

at least Montclair Acura was telling me flatout they use regular for my first tank. they said "no problem". it's really no problem. u lose some power that's about it for the short terms anyway. it's not gonna hurt anything.

 

I've been using 87 and 89 for more than half of my car's life.

I never heard knocking and will continue to use 89 over the winter because I know my car isn't gonna able to put 270HP on snow and icy road.

There is no problem whatsoever with 87 octane. I can feel slight power loss other than that, no problem at all. If someone is going to tell me my car is going to last only 250,000miles instead of 300,000 miles, I am selling mine at around 100,000 so no issues there.

Oh yeah your American premium is cheaper than canadian regular price. So I am saving a lot more money than anyone else calculated on here.

 

I was curious about this...so i called the dealership and it is true...they use regular. Man, that sucks first they jiff us with EL42's now they also skimp on the octane....

 

lol 250,000 miles... no way... even on premium and not without a ton of repair bills.

 

just my opinion...
my mom has a '02 Avalon (ya I know ugly car) but it "requires" premium fuel like the TL. She never put in anything but 87 octane for nearly 70k miles. After about 65k miles, she noticed and commented to me that the engine would knock when she accelerated hard...and soon after that, 2 of her O2 sensors went out and the dealer said the cat. looked very bad for its age.

I know the computer can compensate for the lower octane, and it is made to do this on a temporary basis, but for the long haul, I would say you are risking doing some damage to your car and its just not worth saving $3/tank (her repair bill was nearly $700). I am not talking about power gains or loses - those are minimal at best.

it could be all a coincidence, but running the lower octane may have had something to do with it. most of the articles on this are only talking about immediate or at best short term results (like this thread), I just dont think long term use of lower octane gas is a good idea in cars that are made for premium.

 

There is more at work here than just low octane fuel. Knock is just pre detonation of the fuel. It can be caused by any number of reasons. If you mom is like mine, she drives like a grandma. Slow acceleration and not going WOT every once in a while will lead to Carbon deposits causing hot spots in the combustion chamber. These will preignite the fuel mixture and the cars computer can not compensate by retarding the timing enough to stop it. In addition, since she used lower octane fuel, she probably also bought gas inexpensive gas stations that don't have as much detergent additives in their gas like major brand gas stations do. These additive packages discourage carbon deposits from building up. in the combustion chamber.

As for the Cats, when an 02 sensor fails the computer usually goes to a rich cycle because a lean situation is likely to pop a hole in the piston. It doesn't take long to foul up your cats when burning a rich fuel mixture.

 

Neorick, thank you for your experiment. I think I have definitely learned something about our car here. Just for the record, I don't think you hurt your car by doing this, especially since by design the engine changes its function with suboptimal fuel.

I'm just thankful I can still afford premium fuel.

 

So you are advocating the ole take her out on the highway and blow the carbon out of her now and then rule...

So you guys with nanas running around in TLs should make sure she buys that expensive gas to go to church on sundays. For those of us to see 75 or so on a reg basis we should be ok...

From what I hear (and I am not a chemical engineer) is that all gasoline now have some detergents in them. About 20 or so years ago only the premium had detergents or more of it. There was a recent study done where that for the most part all gasoline sold (with the exception of octane ratings) were basically the same. They also said that if you got pete's gas vs sunoco, you were not getting anything from paying more and getting the national brand.

The more it costs the better it is and that's the bottom line!!! circa 1989 Tommy Cruise in cocktail... The yuppie poet. And no, I have not been drinking today...

Seriously I do not give it much thought. I have run 89 in the car but never 87. As a young child though I recall the days where there were not any knock sensors and computers to control the engine. Mom put regular in dad's Oldsmobile's rocket V8 and it was a rocket no longer. A hold the size of a dime was punched on one of the cyclinders. I recall that and have second thoughts when I gas up. Save the 3 bucks on a tank or...

 

ah yes! the old "Italian" tune up. workes everytime

your correct in saying that all gas has some sort of additive package. Major brands usually have an additive package that is a bit more aggresive in cleaning out the fuel system.

 

I'm just a cheap ass I have been puting 87 in my loaner TSX until i get my new trancemission put in my CL-S

 

bottom ___________" only way to tell the difference in performance is to dyno the car with 87 cotane and after with 93 octane"....otherwise our "feel-o-meter" will not be able to tell if the car has cheap gas or Premium?... good to know since based on "Summer gas prices meter" next year will be paying close to or up to $5/ gallon...did you know that France's prices are over $7 euros...ouch...

 

I can definitely feel power difference between 87 and 91. It's hard to tell between 89 and 91.

I hear every gas station in an area gets gas from same refinery, same truck. When truck arrives at gas station, they add propietary detergent to them. So basic gas is same but you get different detergent depends on gas station. Who has best detergent? no one knows.

Now, what I don't know is how much detergent do we need to keep the car going good? Major players in market advertises their premium fuel has twice more detergent than regular or plus grade. (In Canada). They tested and said premium reallly keeps cars clean(of course this must be biased).

What I do is put 87 in winter.
1. because there is so much snow and ice I can't ever use all the power from engine.
2. I will be idling a lot more because everyone drives slow due to road conditions.

and get 89 or 91 in summer.
1. 89 when I do city driving because I will be idling half of time
2. 91 when I go on highway because this gives me extra 50 miles or so

 

All I wanted to do here is to perform an experiment that most 3rd Gen TL owners are afraid to do. I am not advocating the use of lower octane and am also not saying that premium is better. I know that the car can hadle the change in Octane...the only thing I was worried about is warranty coverage.

Anyway...thanks for all the comments positive/negative....I took a shot for my fellow 3rd Gen TL Owners.

By the way...I am using Dunlop FM901 excellent grip but with a minor road noise. I also change the rear swaybar to Comptech which I highly recommend because of better handling.

 

This thread begs the question - has anyone put higher octane in their TL's for a few tanks? I am talking about getting special gas that is 95 plus. I wonder if would make any noticable difference - I doubt it, since its tuned for 92-93 ocatne.

 

Why anybody would dump low grade gas into an engine that has such high compression makes no sense to me. The computer does its best to compensate when people dump crap into the tank, but that doesn't mean it can't hurt it long term.

I had no choice once but to put in regular unleaded because I was on fumes and the station was out of everything else.
Never has the car so poorly, ran few gallons out and got the good stuff back into her and you could feel the difference.

I've heard the arguments many times, usually people whop know nothing about engines but claim too. Acura doesn't tell you to use the good stuff to lie to you, there is a good reason for it, compression is the main one.

 

I'm personally surprised that fuel economy was unchanged. Doesn't retarding the spark usually harm fuel economy? Perhaps the spark only had to be retarded under high load situations, which weren't common enough to have an impact?

 

Well, I think that 2 months/7 Full tank of regular would have no drastic effect in fuel economy. Now let's say we continue using regular for 6 to 12 months, then maybe the fuel economy will change a bit. Retarding spark..I guess was prevented by computer (Im no Geek so I dont know this) system adjusting to the lower octane. This was a short experiement and only wanted to see what would happen. I am back to using premium and did notice the smoother response.

 

You won't notice any power or fuel economy difference if you stay at low RPM and load.

Once the engine has to really wind up, be prepared to watch the gauge drain and the car to feel sluggish.

 

So then I guess the real answer to whether premium makes sense depends on driving style. If I owned the car, I'd need premium

 

How on earth do you manage 26 miles per gallon in SF?

 

It took about 6 months of using the "regular" gas for my car to start having a problem. It started knocking and missing, it was really bad. Switched to premium gas immediately (actually added octane booster to the cheap gas in tank) and have only used premium since (about 4 months). Not only has the knocking and missing disappeared, but I get about 100 miles more per tank of gas than with the cheap gas (mixed highway and in-town driving).

Everytime I fill up, the added cost drives me crazy but I wouldn't put anything but the premium (not mid-grade) in my car ever again - barring some sort of emergency situation.