Pure Adrenaline

iTrader: (2)

Okay, not exactly regular gas, but I made a long trip today (and only half way to my destination ) and without further ado, here it is.


On 93 octane from Sunoco = 29.6 mpg

On 92 octane from Speedway = 27.5 mpg

On 91 octane from Kum & Go = 25.x mpg


All in one day, consistent driving around 80 mph. If anything, I drove more conservatively on the last tank with 91 octane because the traffic became lighter as the day went on.

That is all.

TLsu

Nice work.

chewi

I thought the higher the octane... the lower the MPG....

TLsu

Unless you were being sarcastic?

chewi

HMMM I think I have a misunderstanding of Miles Per Gallon(mpg).

I thought........ the higher the mpg the better.
And he got the highest mpg on 93 Octane....

I was told that higher octane will burn the fuel faster than lower octane.

Someone please define what mpg really means.....
I feel stupid now.

Ken1997TL

I've had similar experiences in the '97 TL and the '03. I have not tried regular gas in my '05 TL, I simply do NOT trust it in an engine with that kind of compression ratio.

chewi

Is a hIGH mpg good or bad?

ace2525

good...how could getting more miles per gallon of gas be bad

SwampGas

When you take the ratio of miles to price, it's pretty even. It's a matter of how you want to treat your engine and how often you feel like getting gas.

fsttyms1

High MPG is GOOD. MPG= Miles Per Gallon.
Higher octane will not be used up faster than lower octane.

mclarenf3387

You're right, MPG=Mile Per Gallon and more is better.

Octane rating has to due with the combustability of the gas. The lower the rating, the less pressure it can withstand before combusting. If the gas ignites too early, it creates knocking which will damage your engine. So the higher the octane, the higher the pressure it takes to combust the gas. This is why high compression engines need higher octane, to deal with the amount of pressure in the combbustion chamber before the spark is ignited. Although with the advant of knock sensors, damage from knock is no longer a worry, the engine will compensate for the lower octane, but this will result in less than optimal conditions, causing you to lose performance and fuel economy.

TLsu

^^^^

Thank you...makes sense to me now!

RickRoush03

plain and simple, i a car reguires reg gas, put in reg gas, you waste your money with anything higher, if a car like ours reguires premium, you put premium, results are above and the engine is designed to burn 91+ b/c of a higher compression. if you can afford the car, you can afford the gas.

zibadun

also the engine octane requirement is lower in low temperatures, so you might be ok with putting even 89 in the winter without any effect on performance. I wonder if a way to tell is to see if computer is retarding the spark timing with lover octane gas? Also I've read that an engine with carbone build-up would require higher octane fuel due to lower volume/higher pressure in cylinders.

pimpravi

is 91 considered regular gas over there? but here in cali 91 is the highest.

so therefore, your not putting regular gas in your car, correct?

fsttyms1

He never said 91 was regular

NSXNEXT

iTrader: (2)

Now you gone and done it PA. Your car is soooo f'ed up now.

Mr Hyde

LOL, seems like alot of people dont get it. This was a sarcastic post in response to all the posts about running regular gas in the TL-S.

P.A. was just showing how in his case, running regular wasnt saving him anything due to the lower mpg.

Get it???

Da_iLLeZt_TL973

^^nice way to clear it up lol........my parents have been puttin regular gas in the car since they got it....and now that its mine i still put regular gas but now that i kno the car does not perform as well on regular im gonna have to switch to premium

chewi

I get it....But people said that its a waste of money to put 92 and above octane.

I'm currently using 92 Octane. Would Using 94 Octane increase my MPG?

I guess higher octane will give higher MPG...but the increased cost of buying higher octane to increase a small amount of MPG is not worth the money.

t0ast

Here's my question. It's recommended that the TL takes "premium gas". Well here in Cali, like pimpravi said, 91 is premium while everywhere else premium is 91+. So what does Honda mean when it says "premium" - is it an umbrella term for the highest available, or is "premium" an actual octane number?

bstansbu

I just got my 06 TL and the dealer told me not to waste the money on 91+ octane and just ude the 89 we have here as a mid grade gas. He said hat because where we live, which is above 5200ft elevation that our cars will run fine on the 89. Any thouhts or comments on this? BEN

MikePA

Amazing the information 'hidden' in the Owners Manual, assuming one reads it.

The '99 Owners Manual defines 'premium fuel' as 91 octane or better.

Too bad PA didn't include the cost per gallon, then we could have determined if the increased mpg (NOTE: Increased mpg is good) was greater than the price difference.

The ranges when comparing to 91 octane are because PA didn't have the tenths position in the 91 octane mpg.

91 octane - 25.x mpg
92 octane - 27.5 mpg - 6.2% to 10% better mpg than 91 octane
93 octane - 29.6 mpg - 7.6% better mpg than 92 octane and 14.3% to 18.4% better mpg than 91 octane.

chewi

I think I'm gonna try to put a full tank of 94 octane in my gas tank next time to test and see how much higher is my mpg

hemants

Theoretically, if you're driving at a constant speed, a higher octane gas will allow you to do so at a slightly lower rpm therefore possibly saving on gas.

This is all theoretical of course, because we're all lead foots who drive wannabe sports cars :-)

fsttyms1

You probably wont see it. There have been canadian members who tried running it and saw no gain whatsoever and went back to a lesser (91-93) rating. The Tl was optimized for the 91 rating. (since thats the highes some places like cali have)

Pure Adrenaline

iTrader: (2)

I just got internet access. I'm at my destination now.

The 91 octane rating was a guess at approximately half a tank, but I do have a solid figure on that now. It chimed in at 24.8 mpg.

Therefore, to reiterate --


On 93 octane from Sunoco = 29.6 mpg

On 92 octane from Speedway = 27.5 mpg

On 91 octane from Kum & Go = 24.8 mpg

There were minimal price differences, to be honest. All within or around 5 cents. So on this trip at these particular gas stations, it makes more sense to pump in 93 octane.

However, that's just the issue. In Michigan. we get 87, 89 and 93 (also 94 at Sunoco). As I travelled westbound through Illinois, Iowa, Nebraska and Colorado, 93 was no longer available, and only 92 then 91. The owner's manual says 91 octane or higher. 91 is considered premium. So technically, I never put in Plus or Regular gas; always premium. But as you can see, even within the single category of premium, there are siginificant differences in fuel efficiency.

I can only extrapolate and at the projected fuel efficency at 87 and 89 octane.

And yeah, my car ran like shit. I could feel the engine having a hard time. It didn't feel as peppy as on 93 octane. This could be from other factors, such as increasing elevation as I travelled westbound, or the time it took to adjust (but ignition timing adjustments should be pretty much instantaneous, so ), etc.

And yeah, there are ways to monitor the ignition timing. It will require a scan tool (not your average OBD2 scanner.. I'm talking like a 2,000-dollar scanner), or an advanced engine management program with real-time data. As I have said here before, when I was travelling to Nebraska for the Integra Expo, we could only get 92 then 91 octane, and the real-time data on the Apex'i Power FC Commander on my friend's Type-Rs showed, on a real-time basis, that the ignition timing was being pulled. When we could only get 91 octane, it was showing as much as a 35% retard compared to 93 octane.

So I hope this aids in some way or other in putting an end to the "premium worth it or not" debate.

TLsu

Nice work...and thank you for your efforts!

TLsu

Up next, Rob puts in 87 and 89 octane...in the name of science he said he will!

Pure Adrenaline

iTrader: (2)

Over my dead body.

I was muttering swear words as it was, because I had to put in 91 and 92.

fsttyms1

Try being me. Ive got 87 in my tank (Thanks mom, i know its the thought that counts)

Pure Adrenaline

iTrader: (2)

by the mom

Poor Kris.

fsttyms1

dont make me wait for you to get home and fill your tank wit 87!

Pure Adrenaline

iTrader: (2)

I'll pee in your tank.

TLsu

You would think she would know your car/you put in 91+...it is a "luxury car" and you are an ethusiast? My mom knows I put the premium fuel in

AsianRage

My father's been proving the theory that higher octane = higher mpg. He uses 91-93 octane gas only on his Accord and gets easy 340miles on one tank. He switched to regular for a few pump and noticed that he could only get 300+ then had to fill up.

erdoc48

Use what's recommended in the manual (91). It also depends on the altitude where you live. I live in NJ- super or premium is 91 octane/ regular is 87. Where my brother lives in Colorado, premium is 89 octane and regular is 85. More octane is not necessarily better as octane is essentially a flame retardant. That 104+ stuff sold in stores is useless unless you're running a racing motor with extremely high compression. All the ads that indicate 'our premium gas is better because we have detergents' is a bunch of bunk. All gas has to have detergents by federal law. Also, people who use 93 vs. 91 and feel a difference in acceleration...I think it's all subjective.

derrick

Not his fault ... in Canada, we measure fuel economy the INVERSE of the US system. For instance, you guys measure in distance / volume (miles / gallon). Up here, we measure Liters / 100km (volume / distance). So in the latter, you get BETTER fuel economy when the number is lower (ie you burn less fuel to run the same distance).

But the whole thing about higher octane burns 'faster' ... don't know where you got that info from. Higher octane burns more efficiently than lower octane -- maybe that's what you meant to say?

fsttyms1

Gotcha

ZeroPSI

Thats really odd. I get 30+ MPG with 89 octane with Ethanol Blend (10% Ethanol). 91 octane usually nets about 25 MPG or so.

91 octane is the highest they have in Nebraska and Iowa.