I don't care what other people are putting in their cars. Most people lease cars these days and kill them. They red line, they rev them hard when their cold, they go over bumps without slowing down, women drive them (ok, that's another topic!)...etc. Putting regular fuel in this premium fuel recommended engine is the least of their worries.

 

heh, me too. never knew red means sarcasm, is this confirmed?

 

They should just make the TSX blow up with anything less then 91 and save a lot of this debating. I said yes, it should void all engin warranties if you use less too.

 

It is used a lot in the Off Topic forum. I have been posting there too so thats how i know. I think its just finally making its way around to the rest of the forums bc i barely see it used in the TSX forum.

 

Maybe Sunoco's 93 has a higer concentarion of ethanol than their 91. Did you drive exactly the same kind of miles on with both tanks? What kind of difference did you see? How did you calculate your MPG. All things being equal (but octane) I seriously doubt the TSX will get less MPG with 93 than it would with 91 -- that said, I would not expect 93 to get you any additional MPG or performance (over 91).

 

Everyone with a TSX can afford premium fuel. In fact, anyone that drives should be able to afford premium.

Since the difference will probably be +$300~400/year using premium over regular, would it really be THAT bad?

 

it wasn't a significant difference, it was both highway mileage at cruise control....appriximately 1.5 mpg difference, calculated by myself.

 

all great points. NJ driving will do much more damage to a car than using 87 octane fuel!

 

I just threw up in my mouth...

 

ethanol fuel reduce MPG. it's octane enhancer, so 93 may has more ethanol than 91. i recall reading an auricle that running higher octane than require lead to carbon deposit due to lower temperature in combustion

 

Hmmm...I'm sure what you say is true, but even if I was leasing, I'd treat my car no differently than I do now. I just don't understand that mind set. I treat my machines well, whatever they are.

 

I've put nothing but Canadian Sunoco 91 in my TSX in the 24,000KM/15,000miles that I've had it, and averaging about 20.88mpg. I recently went a 900KM/530miles road trip to Michigan and filled up with US Sunoco 93 on the trip back, I got 23.5mpg on the way there with 91 and 26.6mpg on the way back with 93.

As a side note, after I'm done my engine mods, and the gas stats are stable, I will be changing to Sunoco 94 to compare for another 20,000KM or so.

 

 

gogozy and HoRRo,
I realize that ethanol doesn't have the energy density of gasoline so therefore the higher the ethanol content the lower MPG -- even if the higher ethanol gas has a higher octane (and it most likely will). When I said "all things being equal" but octane I was talking theoreticals. It's probably not even possible to have a 91 octane gas that is "equal" to a 93 one in all ways (but octane).

As far as comparing milage when driving to/ from some city, there are a lot of factors that can make the milage different when going to versus from (like differences in wind, altitude, traffic, etc.).

 

i always fill my tsx with prem.
my question is does the brand of gas matter? is shell for example, better than a bargain gas from somewhere like costco?

 

i think this topic is the #1 discussed topic on here. I think with this thread it took the lead on the '6MT vs AT threads' and the 'TSX vs mazda6/TL/3series/IS' threads.

 

yes they are different . top tier gas is gasoline that has the recomended amount of detergents in it. BMW Honda and some other car companies got together to set a standard of cleanliness in the gas that they recomend that we use. those companies are Chevron, Shell and some other but i forget.. I just stick to chevron 93 and boy does it get expensive. today my gas light came on and I drove a good amount before filling up (Id say when i turned on the car, the needle barely moved) then finally went and DAAAMNNNN my bitch was thirsty $50.00 for 15.259 gallons..... I just hope it last me more than my normal 200 miles per tank. I just got to stop driving like an animal...

 

premium when i bought the car was going for about 1.50-2.00 MAX...

Big difference between that and the 3.20/gallon these days...

 

more and more articles report on how there really is no difference in the gas, whether it's a well recognized brand, or a no name. vallero is one of the biggest refiners in the world, and just started opening stations. they are 20 cents cheaper than the brands. i've filled up a few times when i was near them, and i notice no difference in driving, and the same mileage.

that being said, i like sunoco the best, but i'm sure it's all in my head. i refuse to by exxon/mobile or chevron because i hate those companies.

 

http://www.toptiergas.com/

 

funny how sunoco isn't on the list, yet NASCAR uses it.

 

Thats crazy!!! yeah they got conoco/sonoco sounds the same.....J/K I didnt know nascar uses sunoco....

 

wtf? I didn't realize testicles conferred omniscience.


All this time, all I needed was a set of 'nads.

 

"Don't afford premium" is not appropiate IMHO.
"Don't want to" are more likely in their mind.

 

When I first got my 2004 TSX I was putting in 91 octane. My gas mileage avg was around 23.5 mpg for the first 10,000 miles.

I then switched to 89 octane and my mpg improved to around 25.8 mpg.

I wondered if that was simply due to the fact that the motor was more broken in. I switched back to 91 on one tank and notice again a drop off in mpg. So I went back to 89. Always use Chevron.

My TSX is a lease. I rarely ever punch it. It's a daily driver. I have like 29K now. I don't think I am hurting the car by putting in 89 octane based on my driving habits. The TSX is slow to me anyhow since I have a 2001 BMW M3.

That's where my money goes and I use 91 octane and even put in a bit of 100 octane racing gas to give me around a 92-94 octane avg which the M3 operates best.

As far as why I leased the TSX....I simply don't want to go through the hassle of selling it or trading it back to the dealer and possibly getting raped there. Time = Money for me.

 

I really don't see your point, after all NASCAR still uses LEADED fuel!!! Not to mention they haven't even figured out what fuel injection is yet!!

 

I had my doubts about the higher octane because I've never owned a car that required it. But after reading about it here and other websites, I've decided for the most part to put the higher octane in the tank. On occasion, if I'm feeling especially cheap/broke, then I will put in the mid-grade or maybe I'll mix the two. I'm not going to feel guilty for doing so. I also live in a higher alltitude area so my octane choices are lower than others in the country.

http://www.cars.com/carsapp/national...odaysgas1.tmpl

 

And a cock. You'd look a bit funny with just a set of nuts swinging...

 

Hmm, that's odd. Maybe next time you should have a blind test done?

Have someone fill your tank with 91 or 89 and just test your MPG for about 10 fills.

 

 

who cares...its not my car...as long as they put the right fuel in mine no biggie...on top of that its a RECOMMENDATION not a REQUIREMENT like the grade of oil used in the engine...91 is best but 87 works too

 

^^Just keep telling yourself that dude.

 

i agree, it says recommended, not required.

 

The 05 TSX I just bought has 8200 miles on it. 2 questions - Is there any way to know the type of fuel that has been used? If the previous owner has been using 87 octane, will my engine recover to its full potential if I use 91 from this point forward?

 

this is so funny, and eyou're going to get every answer. i believe you're fine, especially with such a young engine.

 

Just run a little of this through the lines and it will clean it right out... j/k

You'll be just fine even if there was 87 in the car previously. Just use the higher octane from now on.

 

That's funny, right on my tank door it says in bold "PREIMUM UNLEDED FUEL ONLY"

Dosent sound like a recommendation to me...

 

But I'll save $1.20 on my fillup if I use 89.

 

I agree with that too. If diesel is cheaper you should try using that

 

On the nightly news last night they discussed this exact topic. They went to various gas stations and interviewed people that were putting regular into cars that required premium and if they were worried about the possible consequences.

My favorite part was the woman that proceeded to fill her Jaguar with regular because she said she just can't afford the extra .20 per gallon for premium even though her car requires it. She said she would not be able to buy groceries and pay her bills etc...

Ummm... Hey lady... if you can't afford .20 a gallon extra... might want to look at other areas to save money... like your car payment!!! Perhaps a Geo Metro would suit her better? What a dummy.

But they then went to a few garages in the area and asked their opinions on putting a lower grade of gas into cars that required 91, 93 etc... Most of them said they would be hurting the car as it would not run as clean. Still remains to be seen as to how much damage it can cause over time.

I am not taking any chances, my car treats me well so I treat it well... for the extra $18 a month it costs me to use premium, I am not going to cry about it... Just have 1 less beer when I go out on the weekends... problem solved.