(Cliffnotes on the bottom)

I remember there have been many posts about what gas to use in the TL with many people using premium and some people saying regular is fine. Well after dd'ing the TL for about a year now and trying out all kinds of different gas I can give my experience (and advice).

I've always ran premium (93 here) for the first 9 months or so since beginning of 2010. However with the gas prices going up recently and having to fill up sometimes twice a week has tempted me to use lower octane gas. Slowly I tried using 89 without much changes in mpg or performance but not long enough because it was not that much cheaper than 93 so I started using 87 for maybe a month or so.

At first all I cared about was gas mileage since I was doing a lot of driving to work. I was averaging about 22 mpg with mixed driving on the premium. The 89 and the 87 both have returned similar mpg and surprisingly not lower like others have stated. So I ended up thinking there was no point of running premium gas since the mpg's are the same. However when I was running the 87 gas the car felt like crap. The car felt powerless when accelerating and it drove pretty rough. The throttle was so dull that I had to step on the gas halfway for the car to downshift. At highway speeds (only 60-65) the car felt like a 20 year old 4 cyl econobox struggling to keep the speed up and the whole car felt very shaky and unstable.

So I decided to go back to 93 to see if it was related to using regular gas and it definitely was. After switching back to premium the power came back and the throttle response was a lot sharper. Not only that the car ran MUCH smoother especially on the highways. No more unstableness only at 60-65mph, but even going 75-80 it was smooth and firm. I actually enjoy driving the car more now and feels like I'm driving a whole new car.

I know most of you guys use premium but if anyone is tempted to use regular don't do it. I used to not believe the regular/premium myth but after experiencing it first hand I could safely say these cars need premium for sure. Oh and I only have a tl-p so I imagine this is a no brainer for tl-s's. Sorry the story got a little long but just wanted to share my

Cliffs:
-Drove the car on 87 gas for about a month due to increase in gas costs
-Noticed same mpg so thought it was fine
-Car drove terrible, felt like had no power, dull throttle response, struggling at only 65-70 mph.
-Switched back to 93 and the car gained back the power and smoothness. Enjoyable to drive once again.
-DON'T USE ANYTHING BESIDES PREMIUM!

 

I agree with you. You actually only save 4-5 bux after a full tank. My car looses any low end that the 3.2 is already low on as it is...lol. Mid range is similar but then there's the lack of top-end power.

 

the car is designed to run on 94 octane! but will adjust itself and deal with 91
any lower is a problem as discussed -retarded timing creates pinging etc

type S cars with their 11.something to 1 compression are just asking for trouble running less than spec gas

 

If you had that many issues (powerless, rough, dull, struggling to maintain speed, shaky, unstable, whatever else) you must have had more problems with your car than just the octane rating of the fuel you were using.

 

can't tell you how happy i am that gas prices are on a fast rise once again. fuckin a.
/s

 

old plugs, dirty injector system and carbon loaded piston tops would all combine with low octane and the ECU response to it--
let you know saving a few dollars really wasnt worth it

 

My dad ran 87 for about 5 years straight, right off the dealer's lot. When I first got the car I drove it as far as I was willing to risk, and I filled it up with a top tier premium gas (91 in AZ). I got a CEL the second I turned on the car. It figured it out by the next fill up, but if you change octanes, I can only imagine a simple ECU reset will speed up the process.

 

LOL i've never even seen 94 octanefor sale anywhere. Max I have seen at the pump is 93, and thats rare out here, mostly 91.

 

We normally have 91 octane everywhere here in Canada however you can pump ultra 94 Octane at one of our common gas stations..

 

94... that er stuff used to be everywhere up here eh?
Chevron only has it now, used to be at all stations pretty much - but that's just where i live.

conspiracy: aspec ->canada, 94 gas -> canada

 

it's actually only like $1 or 2 iirc, but yes when you do the math, it's not really that much more for better gas

we only get 91 here


and FYI, it's 10.5:1








also OP, maybe you should try some SHELL gas too, same thing happened to me as to you switching the octane's around when i switched (i had finally found one near me, and i switched the next tank)
and the scary part is that even the wife can tell on her car, with how it runs between brands (i know people stay it's all the same, but there is enough of a difference; even if it is the same base stock/refinery; that you can feel it though)

 

91, not 94.

 

has anyone ever used octane boost ? If so, what was the experience ? I thought the type s calls for 91 octane ?

 

Drilling banned in the Gulf over and over again, the Alaska Pipeline offline, vast stretches of America off-limits - no wonder the prices are spiking. I paid $3.459 this morning and I was pissed. I drive 500 miles a week.

 

I have been running Lube Control products religiously for about 3 years. I started using it with my EM2. I use LC-20 and FP-Plus. It isn't really an octane booster, but more of an additive with detergents. You put an ounce of FP-Plus in your gas tank for every 14 gallons and an ounce of the LC-20 every 1,000 miles in the oil. It isn't a product that you can grab locally at a store, as it must be ordered from them directly. Check out their site...

http://lubecontrol.com/

 

wife does like 800 a week (she fills up twice a week quite often)

 

I found a couple of years ago that not only does my TL prefer premium gas, it prefers Mobil premium gas. My MPG went up about 10% when I switched from el-cheapo no-name gasoline to Mobil. With the Exxon/Mobil Mastercard's 15c/gallon discount, plus my local station's 5c/gallon coupon, plus 1% UPromise, the price ends up about the same as the no-name gas anyway.

 

it would take 20 dollars of octane booster to do anything for a tank of 87 or 89
If you are racing the TL you already know a station with the ~good gas~

I think compression varies with year--I've heard 11 and 11.5 to 1 for type S??
mere wishful rumor??
regardless, its over 10-1 and clean pistons are important!!

 

All the TL series call for `91 or above` octane gas

says so in the owner book, and right there on the gas cap door

 

Nice write up. Your TL and my accord have a knock sensor. Your ECU adjusts and will retard the timing while using 87 octane to prevent knocking. It is just not worth saving .20 cents per gallon at the expense of performance and possible engine damage.

 

it all depends on your territory..

we have some 94/95 here.. but its 93 in most places.

 

VTEC will NOT engage with 87 octane. i tried this once, there was some knocking and there was no vtec at 4500rpm.

 

It should, mine does (the few times its been in my tank)

 

You would spend more on a bottle of octane boost than you would filling up with 91 over regular. Adding it to 91 wont gain you a single thing other than empty pockets.

 

the RL has 11.0:1

and the type S was only two years (at least for our generation of cars), so i don't see how it could vary very much


but yes the type-S is on the higher end of compression of mass produced cars, so as much as possible needs to be done to keep the combustion chamber and piston "clean"
(and i have seen a non-interference motor, bend valves before, basically because of the carbon and such built up on top of the pistons; got 12 of the 16 valves; owners where cheap, and you know that had run cheap gas regularly)

 

I have NEVER heard or had this happen to me. Low oil will cause VTEC to not engage. Especially if you are in a goo turn and most of the oil will shift to one side of the motor causing the VTEC oil sensor to detect no oil. To protect the motor, the ECU retards timing as if u hit the rev limiter mid rpm range.

DOHC VTEC motors won't go into VTEC if motor is not at operating temp.

 

sure...


but yes it will red line at 6k roughly, when the oil sloshes around (i found out, when i was burning a shit load of oil, because of how i was driving [ 2 quarts in like 2000 miles or something stupid], my oil level is staying up now, now that i am not redlining it as much and staying in VTEC )

 

Vtec motors carry a lot of oil up hi. Vtec motors will burn 1 qt of oil between oil changes. Normal Drive and enjoy it. I Honda didn't want you to rev it to 7k, 7.5k, 8k, ore more. They wouldn't put redline there. You you nothing to worry about. I'd do synthetic though and you'll not burn as much. Royal Purple is my pick as it was made fore hi revving motorcycles.

 

that was ON synthetic (and burning that amount of oil is actually acceptable by most manufactures ), is was schaffer's oil though, which is still a very quality oil (when i got my car baselined, i noticed the performance shop was also using it too...)


and 8k rpms , done that too....., no ill effects yet from it too

 

There won't be. Hondas are meant to rev. It does it with a glorious sound. mmmmmmBAAAAAH!!!...lol.

 

With the technical arguments for/against filling up regular gas - could it be possible that the noticeable differences may be due to a placebo effect?

Just to play devil's advocate here - next time going to the pump, you should step inside the store and get something while you have a friend fill up the car for your, without telling you what they're putting in. Then have you guess if the car is running on regular or super. Do this about 3-4 times (you don't even have to fill up, about $15-$20 worth) and see if you're accurate.

I mean, dirtying up the fuel injector system, spark plugs, etc. aside - most of the obvious differences (like quicker pedal response) may just be in our heads.

 

No, it is definitely not just placebo. My dad had been using 87 for about 8 years, and he told me to fill it up one day. I filled up 91. This caused a CEL which I reset. The next day, he asked me if I messed with the engine or something, as it was driving "differently."

 

What was the code set?

 

The Shell 93 gas has NO ethanol in it, which maybe why one might notice some difference running it.

 

There is a station in my town that sells premium gas with NO ethanol whatsoever. Gas mileage is back up and the engine feels more powerful.

 

I didn't know that- will have to chk. local Shell-

 

interestingly, the Coyote V8 used in the new mustang has 11.0:1 CR, but runs on 87 octane using an "adaptive spark control"

 

all i am going to say, is that 8-9 years of engine design, and computer advances does wounders for controlling knock and such, and actually air-fuel ratios sensors help too, instead of old-school narrow-bands








and that engine will be even more critical to keep the internals clean to prevent pre-ignition and such

 

my friend a couple days ago tried to convince me there is no difference between the two and that im just wasteing money.

 

theres no way imma pump anything lower then super! hahaha almost got me there!