thetaylor310

My last full fill-up resulted in some encouraging results:

- 577.2 miles from full to empty (half tank was at 342 miles)
- 28.1 average mpg

PyroDave

thetaylor, divide your miles by the gallons. our tank has 18.5gal capacity you get closer to 31 mpg if you drove 577 off a full tank. unless i did a mathematical error somewhere

Acura_Dude

WOW! What octane did you use?

thetaylor310

Thanks for the math; it was never my strong suit during school lol
Based on that, i should have an 31.2 mpg average

@Acura_Dude, it was on 91 octane

TSX Rod

I've had a 2004 TSX, 2008 TSX, and now 2010 TSX. I started with 91 premium on 2004 TSX then 89 and then 87. I never really noticed a difference in performance or gas mileage or hear any pinging/knocking. So I always use 87 these days.

I don't "race" my TSX. If people are stepping on the gas hard and going uphill alot then maybe the premium is warranted but I don't know. Bottom line the TSX is slow.

I'm more in line with your thinking of why pay extra when it does nothing. All my TSX's are/were leases. I could care less about the cars after I turn them in. So I have my reasons for using 87.

And for those who say if you can't afford the extra few bucks then why buy a 30K car...I get a good laugh out of this.

I use 91 premium in my BMW E46 M3 (333 hp). I also obviously use 91 premium in my Ferrari F430 (483 hp) and I sometimes mix 100 octane racing gas...just a few gallons.

There's no way a 210 hp TSX should need 91 premium. And for those who are using 93...probably better off mixing or using mid grade.

The TSX is obviously my daily driver which racks up the most miles by far.

Acura_Dude

^ Wow a ferrari and a E46 M3... I wish you were my neighbor, i'd bug you every time I seen you just to look at the cars.

HI NEIGHBOR!

nj2pa2nc

nice selection of cars you have. I own my 06 tsx but use regular gas. After filling up my car at the Wawa in Fredricksburg, Va and driving it to Toms River, NJ the MPG shown were just shy of 37MPG. Runs excellent and I plan to keep alot longer.

ParaSurfer1979

The 93 octane isn't for mpg's it's because of the hi compression ratio. The same engine in the accord on 87octane because its lower compression (10.5 to 1) is 11hp/10tq lower than the TSX so in theory you guy's 2nd gen TSX running 87 are in turn running a 190hp/161tq vs. the 201hp/172tq you would have available with 93 octane. To each is own but you guys and ladies that have modded TSX's it def does win to push 87 into those engines. The K24 responds very well to mods (that including gasoline). So for those running i/hdr/exh, I'd stay away from regular grade.

Now that said, I own a TL but my i got my mom to get a 04 TSX when they came out so i know all about your cars. If I am low on $.$$ and im trying to get the most gas out of my funds, I will drop down to 89 but the low-end performance is really affected so things like passing times on a 2-lane road for example are def slower and takes more time and preparation than with 89. This has been a very educational & informative thread. I just fine the extra pep more useful than not having it. The TSX is very sensative to things like gas and intake temps of which the ecu retards the timing greatly. On a very hot season like this past summer it would be hard to notice the advantages of premium fuels due but on a cold night the timing is advanced to the max and the engine is getting very dense air for a more powerful combustion in the cylinders, you'll def notice a difference in power.

northwoods

My 2 cents...

was told by the acura service manager that mid grade gasoline was fine...

i now have 140,000 miles on my TL type S...no problems, no pinging, no
dieseling after 9 years...

donavo

just because its "recomended" to use premium, doesnt mean u should use regular. all this is just an excuse to use regular and justify it for people that are too cheap to buy the best for the car. i for one take care of my cars. not one car ive ever drove has had anything but 91+. be it a corrolla, previa, or whatever car i happen to fill up. especially my own cars. sure there probably wont be any difference but i would rather get the better. its only like...30 cents difference.....

thailander

iTrader: (1)

My owners manual for the 2012 i4 say it's required instead of recommended

Acura_Dude

Premium is a waste of money especially when it's not recommended nor required. Using it in a car that recommends 87 doesn't make it better, just more expensive to fill up.

turning japanese

Directly from the 2012 TSX Sportwagon (same IL4 motor) owner's manual:

■ Fuel recommendation
Unleaded premium gasoline, pump octane number 91 or higher.
Use of lower octane gasoline can cause occasional metallic knocking noise in the engine and will result in decreased engine performance. Use of gasoline with a pump octane less than 87 can lead to engine damage.
■ Top tier detergent gasoline
Because the level of detergency and additives in gasoline vary in the market, Acura
endorses the use of “TOP TIER Detergent Gasoline” where available to help
maintain the performance and reliability of your vehicle.

http://www.ftc.gov/bcp/edu/pubs/cons...tos/aut12.shtm

On the other hand, a re-branded product with a premium label does get some people excited to part with their money. It makes them feel better. And it's called Marketing 101.

WheelMcCoy

@Cylanth

You need a more precise testing method.

1. Get tire pressures to spec
2. Reset ECU by disconnecting battery and reconnecting it
3. Drive with 87 Octane -- 3 tanks, and refill at the same pump.
4. Calculate mpg by dividing miles travelled by gallons used. Don't use the car's computer.

Repeat all steps with 91 Octane.

Or you can just watch this really cool YouTube video from Fifth Gear:

It talks more about power than mpg, but it's informative anyway.

Acura_Dude

That's true.

maryv1

I have been looking to purchase an Acura TSX and thought I'd do some research. Stumbled upon this website. I just wanted to answer, with what limited info I can give, but my 4 cyl Honda Accord EX prob has the same engine as the Acura TSX. I've been using regular since I bought it 5 years ago and have never had a problem with performance or knocking, etc... Hope that helps someone.

thunderbt3

Basically its the same engine, but it's also not. The Accord K24A1 engine is not a high compression engine where the TSX K24Z3 is high compression. Since it's a high compression engine, Honda recommends high octane/premium fuel to prevent pinging and knocking.

stan_t

K24A4

Found in:
2003-2005 Honda Accord(USDM), 2003-2006 Honda Element
Displacement: 2,354 cc (143.6 cu in)
Bore and Stroke: 87 mm x 99 mm (3.43 x 3.90 inches)
Compression: 9.7:1
Power: 160 hp (119 kW) @ 5500 rpm (166 hp in 2007/2008)
Torque: 160 lb·ft (218 N·m) @ 4500 rpm (@4000 rpmin 2007/2008)
Redline: 6800 rpm
Cable actuated throttle

K24Z3

Found in:
2009+ Acura TSX / Honda Accord / Honda Accord Euro (CU2)
Displacement: 2,354 cc (143.6 cu in)
Bore and Stroke: 87 mm x 99 mm (3.43 x 3.90 inches)
Compression: 11.0:1
Power: 201 @ 7000 rpm
Torque: 172 lb·ft (MT), 170 lb·ft (AT) @ 4300 rpm
Redline: 7100 rpm
Drive-by-wire

Basic engine design is the same, but it is not the same engine by any means -- 9.7:1 compression ratio vs. 11.0:1 is a big difference, and the differences in other specs are there for a reason.

Use premium fuel, manufactures are not pulling your leg.

Stan

BobbyC

only used premium in cars it was "required" in.
in those cars, theres a huge difference when you put crappy 89 oct in them.
for instance, my S2000 used to idle rough as hell with 89 and even stall out for no reason at all.

when i had my FD Rx7, i put 89 in there once, it made it run like crap.

i put 89 in my tsx. never had a problem. she runs smooth.
couldnt tell a difference the few times i put 93 in there so i stuck with 89.

WheelMcCoy

Thanks for the info. Just curious, any idea when vtec kicks in for the respective engines?

VR1

I wold definately use Premium fuel if its reccomended. Not worth saving a few bucks on a 30k+ car using regular fuel.

Pursuit2550

I keep hearing "its not worth the couple bucks you save" "why would you buy a 30k car and complain about the gas". What does 30k have to do with gas? A lot of cars are worth 30k and they dont take premium. Its in black and white "recommend" not required. Another thing I keep reading is "I use premium on all my engines because I take care of my stuff" if you would read more into gas, you would know that a car designed for 87 running 93 destroys it, not protect it. 93 has a high tolerance to knock, detonation, etc. It takes more compression to achieve a full burn. A low compression engine designed for 87 doesnt have enough compression to make 93 burn complete. There for you jave left over raw gas. Now where does that go, well some gets left behind going into your oil, some stays creating extra carbon on the pistons, valves, heads, etc. And then finally some goes through your cats, eventually clogging them and also messing with your o2 sensors. Lets face it for the normal daily driven tsx regular will fine. These cars are NOT FAST, period. Its a sedan with a 4cyl engine. Besides whos had an engine blow up because of the octane they have used. And who keeps their cars till the engine dies?

Pursuit2550

And you think 87 will hurt it, no. Acura already has this programmed into the ecm. Theres more expensive cars and trucks out there that dont require 93. Money has nothing to do with the octane rating. And for all of you that use 93 in a 87 engine, you doing more harm than good. Google it and you will see.

its rayden

so you intentionally want the ECU to retard the timing due to your 87 octane fuel? that's your prerogative. i prefer to have my engine performing at it's best and i would recommend others to do the same

stan_t

Where did you get this information? Higher octane fuel will burn up just fine in a car with lower compression, you just won't be able to take advantage of it's benefits since timing won't advance any more than it's designed to with lower octane in mind.

It will not destroy anything lol, you just won't get any benefits as far as power goes. Now, going the opposite way -- yes, it will destroy things, I can point you at plenty of cases of broken ringlands in turbocharged Subaru engines due to knock (my buddy had that happen). Carbon buildup, pitted pistons, even spun rod bearings and holes in pistons -- plenty of engines die an early death due to running on lower octane than designed for.

Higher octane fuel will provide a slower, cooler burn. Some race gas is added to street cars at track days all the time, it's common practice to increase engine safety margin.

Stan

ceb

The ignorance of some forum members is astounding.

A manufacturer designs a system to use a particular octane rating of gasoline. For the US, there are basically 3 choices

Premium 91/93 (depending on location)
Mid 89
Regular 87

Gasoline in higher altitude areas may be slightly lower. Colorado, for example, has 85 octane which "works" just like 87 elsewhere.

Using an octane rating higher than the one that a system was designed for brings no benefit and may actually (according to a Car & Driver test) lead to reduced performance in Honda products.

Using an octane rating lower that the one a system was designed for can lead to pinging and engine damage.

The above two paragraphs are factual statements, not wild conjecture.

Now, the TSX is designed to be used with premium gas - but - the ECU is programmed to allow for the use of regular grade gasoline with a reduction in power/mileage but with little risk of engine damage.

You may get just a bit of pinging with regular gas and a decrease in power.

Pursuit2550

Re-read what I wrote before you write. I never said that I use 87. I said using 87 will NOT damage anything in your engine. Thats why its recommended not required.

stan_t

Detonation/pre-ignition will absolutely cause damage in your engine. If you feel it is safe to run your car on regular gas, fine -- it's your car and money and may work fine for you, especially if you are a mile above sea level -- but assuring people that it will not cause harm can lead them to ruining their cars, which isn't cool.

Yes, there are knock sensors, yes, ECU should be able to retard timing -- but this is a safety net, not the proper environment to operate in full time; besides, safety nets can fail and do have their limits.

Stan

Pursuit2550

TSX is fine on 87,89,91,93.

Pursuit2550

And who says that detonation will happen with 87. Do you have proof or have you ran a datalog on the TSX with 87 showing detonation. The ecm on cars have a wide thresh holed to compensate for such things. Why do you think they are pig rich on fuel from the factory. And I am not the one assuring people, its Acura. They say anything below 87 will cause damage. They never said anything about 87 causing damage.

ceb

Feel free to run whatever you want in your car. The car was designed for 91 octane while allowing the use of 87 octane without physical damage.

Much of your post makes little or no sense. What is "thresh holed"? Is there a wide hole in your thresh? Does that happen from low octane gas?What does "Why do you think they are pig rich on fuel from the factory." mean?

Oh, a question usually ends with a question mark.

Pursuit2550

Apparently you dont race much. Pig rich means that the ecm is programmed to run richer. Thats why alot of car benefit from a tune, they lean out the fuel curve and add timing. And I meant to write threshold. The ecm is programmed to lean out or richen up the fuel curve and to add or sub timing as it sees fit according to the sensors. Thanks for the education lesson and also for also proving my point "The car was designed for 91 octane while allowing the use of 87 octane without physical damage."

stan_t

I have not datalogged a TSX. I may look into it later down the road, but at the moment I just don't want to commit to dealing with tuning of this car. Been there, done that.

I would not say my '12 TSX is pig rich. I drove a turbocharged Subaru for 5 years, I know "rich" lol. Though, again, I don't have a wideband and am just going by feel.

Trackdays are not "racing", but I get what you are saying. Thing is though, it's very easy to create a high-load situation in every day street driving, especially if you carry passengers, have to climb hills and deal with hot weather and stop/go traffic. In some ways, it's much easier to tune a racecar because there aren't as many variables to deal with.

I just think it's much easier to stick with what the engineers recommend for ideal driving situation, and concentrate more on the road and have fun driving instead of trying to save money on gas. But, that's just me.

My buddy's engine was a stock EJ25 in an '07 STi, stock tune. He always ran premium, but we are in CA where fuel is crap. He most likely hit a batch of bad gas at some point, car knocked and the piston went. Subarus have had issues with weak ringlands since '06 or so, but they don't break themselves, they break from detonation. It cost him $7,000+ and he did all the labor himself.

Stan

Pursuit2550

I do agree on what you have said. I myself run 93 because yes it is a high comp engine and I do step on it a lot. Now if it was a dd that didnt go pass, oh lets say 4k I would use 87 as I will, nor the engine, benefit from 93. If I would have bought this car for the wife I would tell her 87 since she drives Miss. Dasiy and is with the kids most the time so need to speed.

stan_t

There is no way for me to drive below 4K RPM around here, I will get ran off the road by an angry mob in SUVs and Priuses lol. And, we have lots of hills.

I used to drive a 2001 Nissan Frontier with a v6. It was designed to run on regular, so that's what I ran it on. I lived up on the hill and could hear the thing knocking driving home every day, if I filled up with premium it did not knock. Just regular every day driving conditions, nothing crazy -- I can make a car knock around here, I can assure you.

My buddy's piston -- stupid Subaru.



Stan

Pursuit2550

Must suck for your buddy then. I figured cali would have better gas since you guys have all those mandates and epa regs. Down here in miami I have never had an issue with bad gas. I have always ran either a s/c, turbo or like my last truck, nitrous. Then again a good tune is key to not blowing up a engine.

Pursuit2550

Miami is the same way. Thats why I am always stepping on it. I try not to abuse it but coming from v8 with mods its hard to get use to this 4cyl. It not as bad as the beater I had though, a 02 civic. That thing couldnt get out of its own way.

stan_t

We have the worst gas in the country. At least 10% of it is ethanol, which I hate. Only ethanol-free fuel you can buy is race gas at the track, not for street driving. At the pump, we have 87, 89 and 91, no 93. Prices are probably some of the highest in the country even though I can drive to a few local refineries in 30 minutes.

For a while we were promised ethanol stations everywhere, so many turbo folk were all happy, getting ready to convert their cars to it. That flopped, though there are some stations around (not close enough to me to daily drive on it), but E85 is so inconsistent.. a shop I know runs a Subaru in Time Attack on E85, and they test every batch in house.

Anyways, we have to watch our fuel closely, I stick to Chevron (76 if I can't find Chevron) and stay away from Shell and others, though the TSX probably isn't as sensitive to this as my Subaru was.

Stan

Pursuit2550

Why do you stay away from shell? It is a top tier gas you know, unless it deffirent up there or something.. Go to toptiergas.com. it lists all the top tier gasolines. I stick to chevron, shell and mobile, in that order. Yeah that e85 thing was a scam I think. They promoted it like crazy, a lot of cars are flex fuel but its a pain to find a gas station. There are like 3 or so here in miami.

its rayden

isn't shell top tier also? what's wrong with them? i usually get shell, bp or mobil