02CL-TypeS

premium 91-93 octane

nj2pa2nc

the average driver puts on 10,000-12,000 miles a year on their vehicles. I average 30,000+miles on my car. I travel every few weeks from NC to NJ (635 miles one way) I think taxes will also get your savings. I like to go out to eat once or twice a week-(wasted money-cheaper to eat at home)I also like to take roadtrips. Drove from NC to Ca and back-6542 miles and 20 states.

02CL-TypeS

Have you ever even tried premium gas right after a tank of regular gas. 91 or higher octance does truly make a difference. I used nothing , but regular fuel for my 2000 maxima cause I couldn't tell the difference between the recommended premium or regular.

However, with my 02 Acura CL-S I can tell a HUGE difference between even mid grade and premium fuel. I won't use anything other hten shell or BP octane...all they offer is 93 octane around me. I'm payed 4.09 today for 93 octane.

psteng19

I filled up with 89 just for kicks and got 39.3 mpg on the MID for about a 80 mile mostly highway stretch.
I think I may just start putting in 89 from now on

deepen03

i always fill 93 octane or higher (94 at some Sunocos). I know the prices are ridiculous, but its better than hurting the engine. I usually get either Shell V-Power or Sunoco Ultra.

deepen03

yea, but that range isn't accurate because you only drove 80 miles. Once you hit a certain number of miles on your tank, the mpg will gradually drop. That happened to me once and it said i was getting like 41 mpg for about 50 miles on the hwy but then it suddenly dropped to like low 30's mpg.

bradykp

i've tried 87, 89, and 91. i used 91 for most of the time I have owner the car, but lately, with 87 at $3.98/gallon in NJ, I'm using 87. my MPG has not changed at all. i notice a very slight difference in performance,, but it's minimal and I don't think the average driver would even notice it.


the myth that 91 is "better" is simply a myth. your car has an ECU that adjusts the timing of the car for 87, and the adjustment is so slight that there's no way most people would notice a power difference. if you think you do, you are nuts.

bradykp

how exactly would using 91 or 89 or 87 hurt the engine? i'd love to know (especially since premium is 'recommended', not required).

all victims of paranoia.

do you change your oil every 1,000 miles? what if you hurt the engine!

bradykp

i've measured my tank over 300 mile distances and i get the same MPG with 87, 89, and 91, on average. i drive the same route every day for the past 2 months. my mileage hasn't changed at all.

timbo04tsx

BP Ultimate 93 octane ONLY!! I guess I'm just paranoid but I figure why not treat your car right. It's $4.18 a gallon in my area which is ridiculous (20 cent increase over 87) but I pay it anyways.

classical420

^ cosign

odannyboi

use premium, you cheap bastards

nj2pa2nc

If premium improved the gas mileage or made it perform alot better I would use it. I tried using premium for two months-no difference except the fun of spending more money. I will stick with regular (call me cheap)

cconrad

It may depend on how you drive and your environment. Under conditions of high heat and/or "spirited" driving, premium should give you better performance. The higher compression engine develops more torque and/or horsepower (I'm not sure which is related to the higher compression; probably both). However the higher compression requires higher octane gasoline to avoid preignition/predetonation (a.k.a. "ping" or "knock").

In the old days, you could seriously damage a high-compression engine by using a lower octane rating than specified, because of engine knock. However this engine (and probably most modern high performance engines?) has a knock sensor and it automatically retards the timing to stop knock the instant it senses it. This will rob you of some power, but will preserve the engine. So this allow you to use lower octane gasoline at the expense of some loss of power. Indeed, if you're driving under conditions that are not demanding, you may not notice the difference.

From what I understand, high octane gasoline will not improve gas mileage. It's just related to preventing preignition, thereby allowing higher compressions and more power.

All that said, I bought a higher performance car because I like to drive in a way that uses the power it can offer. So I've never put anything other than 91 or higher in it, like the manual says.

Besides, I'm slightly nervous trusting the anti-knock technology. What if one of those sensors or something fails? I know with the high octane fuel it should never get hurt, even if the fancy electronics fail to do their job.

DiaBando

iTrader: (3)

premium. period.

TSXGOTME

Premium period I have wanted to try and drive on regular

club_euro2

I would say use Premium. 89 does effect the performance

prelude358

use Premium!!as our car is high compression motor.if can't afford it why bother buying the tsx in the first place

nj2pa2nc

from having excellent luck with two previous cars we owned that recommended premium gas and we used regular. A 1991 mazda mx-6 GT (turbo) and a 1998 Eagle talon tsi-awd (turbo). When we sold our mazda-it had 250,000+miles with the original turbo, engine, transmission, clutch and the talon had 125,000+miles also with the original turbo, engine, transmission, clutch, etc. They both ran excellent. In fact, when my husband was driving the mazda from NJ to NC the end of 05 a guy in a new5 liter mustang wanted to race him. My husband won. When we pulled into a rest stop, the guy followed us and said how he was impressed with our old mazda. I bought the tsx cause I wanted it. If using premium works for you-excellent.

davidspalding

I guess I'm nuts, then. I have noticed sluggish performance using lower grade gas, but then it might've been lower quality gas as well (warehouse club versus top tier vendor). As long as Shell gives me a CC rebate that brings the price down to compare with BJs/Costco, I'm happy using their 93. All subject to change, of course....

What I haven't tried is Shell's 87 or 89....

jlukja

^^ You're not nuts. I've noticed the same thing with Costco gas. I got around 2-3mpg less using Costco 91 octane than 91 octane from Shell, Mobil, and my neighborhood Vons. The difference between 91 and lower octanes will not be felt in everyday normal driving, particularly if you're trying to get better mileage, but will make a difference at WOT (that one time you have to floor it on a short on-ramp).

biswasd

costco 93 octane has 10% ethanol....here in ohio, they had to put a big b/w sticker stating this on all their pumps.

Acura604

up here in Canada we got Husky/Mohawk stations that offer 90grade for price of 87. it also features 10% ethanol. I experimented with this on FULL fillups and consistently got 560km+ on a full tank. Absolutely no performance degradation at all either.

davidspalding

I just filled up at Shell after putting 8.3 gallons of BJ's 93 into my tank (previously filled with Shell 93). Went 236.8 miles, mostly doing some hypermiling techniques, but a few WOT,... and got 31.2 computed mileage. I guess mixing top tier with warehouse gas every other fill-up won't cost me mileage too bad.

valeratj

valeratj

It also does 34.5 MPG highway while using cruise control

visuelz

On my way to Florida from New York, I got an average of 28 mpg and that is with cruise control at 70. I don't know how some of you guys can get over 30.

sac_32294

what about using midgrade? I average about 24-26mpg combined.

Trent1701

I have always run 89 octane and i average 28.3 mpg. The highest I have got was 37.2 and that was on about a 150 mile trip with 3 people in the car ac on and the cruise locked in on 70 mph. As far as noticing a difference in performance what are you guys using to judge this difference?

CinciTSX

Premium, the prices are down again now anyhow

davidspalding

Old thread returning from the dead ... gives me pain in da head....

Mobil 1 Synthetic ... $8 a quart??? Yikes. I get 6-packs for a little under $30 at Costco, and twice a year or so, they offer a $8 off coupon. Does yours come with a Willie Wonka golden ticket?

With the prices here now < $2.60 for 93 octane (I keep blinking at that and thinking, "Wait, not $3.49 ... $2.49?"), I see no reason to skimp on fuel.

thunder04

iTrader: (1)

I don't understand people buying a luxury vehicle (entry level, but still) and then want to skimp on the fuel they put in it!

I'll admit, when gas prices were at their highest, I bought off-brand gas more often than not (because it was cheaper and convenient), but throughout my ownership I've never put anything but 91 octane gas in the car.

Sure, the car will run on 87 and 89 octane gas, but the lower octane will cause piston knock (whether you hear it or not, it still happens). This is where the fuel ignites prematurely, before the piston reaches TDC (Top Dead Center). This premature ignition of gas, over time, will damage the engine. At what mileage will the damage start to show, who knows. I plan to keep the car for a while and I just don't want to chance premature breakdown because I was cheap and used lower octane gas. I'd rather spend the extra $3-$5 a fill up and not risk it.

I'm not sure how people are getting outrageous gas mileages. My last road trip averaged 31 MPG round trip. With my 5AT, I typically get 31-32 MPG on the highway, and 20-22 or so MPG city (don't really pay attention to city mileage too much). Of course, this is without much effort. I could never imagine getting anything much more than 35 MPG out of this car, unless the trip was all downhill lol!

miked8887

I found that implementing more fuel-efficient driving behaviors (like clumping errands together and taking a smoother route with less stops) is really all we can do to save money on gas, and its not even too much of a difference.

There's nothing wrong with saving money especially on GAS. I don't understand people who say stuff like "OHH the TSX is not for people who worry about gas prices." All the thread-started did was ask a question. And its good information for other drivers to read about even if they stick with premium.

Audioserf

93. Even with gas prices at their highest. I'm not putting that 87 swill in my baby...

human668

I use premium. I don't know if it's better for TSX or not. But it does make me feel better.

zguy95135

91 from Shell only, Arco and other cheap gas is so bad and I can feel the difference just from normal driving.

DuckDodgers

Just discussed this with the dealership service advisor. His take was that the only side effect he's seeing from use of regular is having to open up engines to de-carbon at about 80,000...

Of course, given my opinion of data from service advisors...

nj2pa2nc

I heard the same thing about 10%ethanol but I not sure at what mileage.

afici0nad0

91-94 premium

spoiledkari

I don't really care how much more it costs...I only use premium in my TSX. Why not just pay the extra $2 per fill up to be sure?? I notice a HUGE difference in MPG and power when I use cheap premium gas...why would I think that a lower octane fuel wouldn't do the same thing? To me...the extra 2 bucks is worth it.