techhuman

I got a used car Acura 3.2 TL 2002 model about a month back and this is my first car. I wasn't knowing that the fuel tank lid has the fuel type requirement on it which says only use Unleaded Premium fuel and hence I was fueling it up with regular unleaded having low octane. Initially I felt car vibrating a lot on highways 60+mph and since last 2 weeks I got my CEL lights on. Scanned the codes and I got all 6 cylinder misfires and random misfires.

Could low octane fuel lead to misfire?

I fueled up my car with Unleaded premium today and it was driving very smooth on the street roads. Will check on the highway tomorrow.

Skirmich

It may be only Pre-emptive Codes (Missfire, Not Real just a Warning).

The car will run poorly and vibrate alot on Regular becouse the Engine has a Higher Compression ratio.. It needs PREMIUM to RUN not becouse of some Fancy EGO thing.. Higher Compresion Engines need High Octane Fuel to Run efficiently.

With low Octane Fuel the Explosion in the Combustion chamber is just not enough to turn the crank fast and strong enough to complete another High Compresion stage on the next cycle.

The car will run on Low Octane but at Expense of Heavy loss on Power, Lower MPGs (Engine tries to Run very Heavy) and Higher Heat thus Knocking may occur.

Dont Sweat it too much Just reset your ECU (Un-plug battery or Pull Dash Clock Fuse for 1 Minute) and Run with Premium Only from now on... If the Cell comes back on then it must be a REAL CODE not a False Positive like before.

Big Cope

I ran unleaded fuel in my type S for years with no problems. Even when I ran premium for a while I did not notice a difference in mpgs or performance. I've owned this car for 5 years.

Skirmich

Okay "Big Cope" you are just 1 in a Million that Engine of Yours must be Built with Magic and Fairy Dust...

Using Regular Gas on the Type-S is not only WORST since we have an even High Compresion Ratio than the TL-p you Loss so Much HP in the process is not even funny... A good way to know just how much your car just crap itself on using Regular "Big Cope" is to go to a Strip (1/4mile) then do a Run the best way you can.. I can Guarantee you, You wont even Hit low 15s and Stock you MUST hit 14.5s


Please Use Premium +91 octane and Get yourself a New Car... Well at least if you dont Drive like Granny.

Karanx7

iTrader: (2)

Contrary to what you seem to believe, the car being able to move doesn't necessarily mean that there are no problems.

The car runs on premium. Using lower octane will cause the engine to adjust timing accordingly. You will lose power, and your MPG will decrease in certain situations.

You CAN safely run 87 octane on a TL or TL-S if the ECU has adjusted timing for it already, but you'll just have decreased performance.

Gas prices are getting to the point where using Premium might actually be cheaper than Regular because of the MPG difference.

3.2TLc

Yeah, the ECU will compensate.... but as stated above, these Acura TL motor's are engineered with a higher compression ratio for optimum performance and fuel economy. It's always in your car's best interest to attempt following the manufacturer's recommendations. These cars are not "econo" throwaways ! The motors will run well for a long time if treated properly, even though the tranny's are quirky.

In the meantime, read the "DIY's" and do some of the critical cleaning and a tune up. Use some fuel system cleaner prior to replacing the plugs with NGKs only. Read the owner's manual from front to back and check out the site if you have any questions.

DanTL-S

Would the same thing go for 89 ocatane? I've had to use it a few times when I was in a tight money situation and needed the most gas for my dollar (without using 87).

UKwrath33

My parents 03 type S runs perfectly fine on regular, as does my girlfriends 05 RL which hasn't seen premium since it was bought in 07 and it has 240,000 miles on it. 200,000 of which saw regular gas and motor mounts and the 105k mile service and a bad headlight being the only things she's run into. May be a coincidence but in my experience that's 2 for 2. Not fairy dust. Especially on a better more "premium" model with tons of miles.

Skirmich

Anything lower than 91 will get decreased performance... It wont damage anything since the ECU will adjust BUT you wont get the Performance the car was built for.. Using 89 vs 87 would be less drastic drop in HP but it wont save you a Single Dime, Use 91 and you will get the Desired MPGs the car was Stated to do. You dont Save Money on using lower Octane Fuel and that its a FACT.

Using lower Octane than Recommended will ALWAYS lose power no matter what. You car will Run, Like Shit, But it will Run. If you put a TL-S vs a TL-S one using 87 and the other using 91! Both Stock the 91 will just Obliterate the one using 87 and Get Better MPGs in the Process.

Its like using Race Gas! Higher Octane = Higher HP, Lower Octane = Lower HP on High Compression Engines.. Is not Rocket Science.

No one said the car will Implode and Burst into Flames.. Please READ, Loss in Power does not Equal = Engine Toasted... It means just Loss in Power and MPGs.. In the long run both cars are wasting so much Money using Regular that they will never Offset the loss in power vs money saved, Like Never.

I dont understand People that get Luxury Cars above 35K and then Use Acid as Gasoline... Both cars state Clearly that they Use PREMIUM to Work... Not becouse they are Luxurious they Just have Freaking High Compression Honda Engines.

techhuman

No using Premium didn't work much with my car. It does run smooth and reduced some vibrations which I was getting everytime I drive on highways. But again today while driving on highway at 65+ mph, I got jerks 2 times and I guess the misfires were still there. Earlier the CEL lights were stable, but while driving on 65+ mph it started blinking resulting to switching on the TCS lights. I had to stopped on the shoulder lane, restart the engine.

Is tune up and cleaning the filter easy to do it myself? I am scared as this is my first car and have 0 engineering knowledge of it. What if I do it wrong and it can become worse.

Skirmich

Changing the Air Filter is fairly easy just 2 Screws.

I dont know what you mean with tune up? Like Change Oil and Spark Plugs? If so Oil Change is pretty straight forward and Spark Plugs only involves on getting the right Ratch extension for the Rear Left Plug which is the hardest to get out.

laygia123

Is there a difference between 91 and 93? Since ALL the gas stations around my area has 87, 89, and 93. Not a single place has 91 so I'm force to use 93.

Skirmich

Its better.. Dont worry.

techhuman

Okay I will look at the oil change and air filter change videos on youtube and will try on my own. However I am still scared to change the spark plugs on my own even after looking at the video... what if I leave a connection loose or make a wrong connection.

techhuman

Apart from this if you guys have any idea as to why I am getting such issues, please suggest. I am even getting some constant noise around the engine when the car is driving on 1st and 2nd gear. However at 3rd gear the noise goes away. Today I heard some knocking like sound in between on highway and its was not constant though.

TheMightyQuinn

Spark plugs are pretty easy--one of the first maintenance jobs I did. The only diffuculty is in reaching one in the rear, but it can be done with patience and by following the DIY.

techhuman

Something strange happened today. I was constantly driving on highway at 60-65mph since 2 days back I was getting jerks when I exceeded 65mph. But today after I switched off my car engine and then restarted it again, the stable CEL lights I had went off and didn't come again while I was taking the car in reverse for parking.

I am assuming it because when I fueled up my car with Premium gas, I still had a little less than half a tank of regular gas in it. So it was giving me issues even after adding Premium gas.

But the continuous engine noise and the knocking noise sometimes is still there. Will definitely look at the air filter and the spark plugs this weekend and might change the oil as well to be on a safer side.

Which oil could be the best for my Acura 3.2 TL. Sorry but I don't know much about the car and trying to learn things.

Skirmich

Top of the Line? Syntethic Oil would be your best bet.. Now in brands? Well Top of the Range would be Royal Purple but its stupid expensive.. Next? Mobil 1 Syn use 5W-20 (Harder to Find) but you can use 5W-30 (Easiest to Find) too with no problems.

I would not use; Quaker State nor Castrol... Heck I would use Valvoline before either of those 2.

Motor Oil Filters?
Top of the Range...
K&N < Been using it since 4ever... Part No. HP-1004
Mobil 1 EP
Mobil 1 (Normal)
Royal Purple
Wix

Never EVER use FRAM! No becouse of the Horror stories but becouse it does shit as a Filter.

clynnmurray

My comment may 'bite me in the a$$' but I have used only regular in my 2003 Tl for the last 6 years and have been well satisfied with fuel mileage and performance? My trip mileage consistently is 30 mpg or so and it performs well also. No missing or hesitation whatsoever. I have filled up with premium and not noticed any difference in either mileage or performance.

3.2TLc

Yeah, it'll work....just not getting the optimum level of performance which the Honda engineers built the TL for. Chances are that you would be just as satisfied with a more common automobile than the Acura. How many miles presently on the car ?

HairyMonkey019

iTrader: (7)

So I did a pretty long test. (about 3or4 weeks)
I used to run 87 I got about 26.4 MPG
After reading this thread I decided to do some testing.

I went to the gas station, put in 91 and reset the ECU with the fuse pull.
With LOTS of traffic I got 24.5 MPG.

I had another test with lots of traffic, but my number was about 26.some

Next test I did the same driving as I used to and got about 27.5 <I went WOT once, so this number may be a lil skewed

Now if you do the math correctly, and you the price difference between the two stays 20cents, then the only savings you get out of using 87 is worth a candy bar.

Experience may vary!
I would also like to add, right when I switched over to 91, that's when So Cal decided to get hot -_-

The car runs A LOT smoother now. Before the idle would feel rough/weird, and now that's all gone.

So the people saying they tried out 91 and didn't see a difference... well, I bet you didn't test it properly.


Car is fully stock, other than removed intake resonator and no mufflers.

Yikes

The J32A1 engine has a compression ration of 9.8:1.

Gay-Lussac's law of thermal dynamics roughly tells us that the pressure of a gas and its temperature are directly related. Simply put, when you increase the pressure of a gas, the temperature increases. (This is the fundamental principle that diesel engines are built upon)

Octane rating simply means resistance to burning. If you run anything lower than 91 octane rated gasoline through any engine with a "high" compression ratio, you run the risk of having the fuel ignite, simply because of the temperature caused by the amount of compression, before the piston reaches TDC. This will try to force the piston down when it is trying to move up. Needless to say this will not only result in a loss of power, but could also damage engine parts.

My '00 TL, having 202,000 miles, had a slight tick to it when I bought it. I'm not sure if it was the seafoam, but I've never put anything except 93 octane in my tank, and the tick seems to have smoothed out. The entire engine, the way it revs, idles, and drives generally seems a lot smoother.

Just remember this at the end of the day: Premium fuel is required for a reason. They didn't do it to be jerks and make you pay more at the pump.

Besides, in the late 90s and early 2000s gas was oh so cheap. :')

Supra_Lover

VERY informative

03 tls nc

iTrader: (6)

Honda would not sale a car that would be damaged running on regular gas, that's what the knock sensor is for, to pull timing if knock starts to occur from poor octane, high intake charge temps, heavy load.... So as many have mentioned above with low octane fuel you will not achieve max efficiency or performance. My 96 jeep Cherokee on the other hand runs like crap on any thing but regular because that is what its tuned for.

3.2TLc

Yeah, Honda engineers intentionally must safeguard their automobiles from us trying to kill them.

While they may not operate an an optimum level they definitely won't self destruct in the short term. My old '95 beater Honda Accord actually responds nicely when upgrading to premium on occasion.

mccvii

2003 TL S type - sold in 2012 with >140,000 miles. Always ran 87
2002 MDX - Sold in 2011 with ~185,000. Ran regular until about 170k when she started having sensor issues. One treatment of Sea Foam (in the engine, not the tank) and a couple treatments of Techron cleaned her right up. But, we ran premium for the last 20k or so.

Only maintenance was 1 tranny per car (under warranty) and 1 timing belt per car. Guess I must be another of those 1 in a million guys.

Aman

^ Did you not read the thread?

d1sturb3d119

iTrader: (1)

Has anyone here actually done the math to see if premium vs regular actually saves money?

Very generic example
Assuming you do 25000 miles a year at an average of 25 miles per gallon. That's a 1000 gallons of fuel consumed. Which at the rate of premium gas in SLC is
1000x3.27=$3270 per year
Regular gas
1000x2.99=$2990 per year

You saved 280 dollars per year in change. You'll never see the savings and you'll probably spend it in small amounts on other things. We all know how that happens.

The same money goes into your engine on the other hand. Keeps your injectors clean, keep the tank free of debris, and keeps your motor healthy since you don't have to beat on it as much to get the car moving.

Also after using seafoam in a car it does foul up the plugs so you're looking at an additional 60 dollars if it does cause any issues.

Small price to pay when you maintain your car.


Plus if you don't feel a difference there is something very wrong in your test. Any car feels different and peppy while using premium. Carbureted, FI doesn't matter. The quality of gas changes how the engine runs. Just like quality oil does too. There is a reason why synthetic products react better to different temperature, stress, usage, etc.

TLer trash

Back in the pre obd2 stone age, I worked on an F150 for days trying to diagnose a lack of power. Only after I put regular gas in on my dime, the problem went away. The owner only used premium. As it turned out, the ecm did a systems check by advancing the timing, and looking for knock sensor input. When no knock happened with the premium, it assumed a broken knock sensor, and went to a safe, retarded timing setting. You probably had something similar. It's not like they published any of this shit.

SuperGreg

My overall mileage varies from tank to tank due to driving conditions enough that I can't really see a difference between 91 and 89 octane that is statistically significant. If there is a difference it is very, very small.

Power output with 89 might be less but again, it would take some kind of timing or power output test other than my own perception to measure it. I ran 89 for a year or so during high gas prices and didn't notice anything different after switching back to 91.

coronaman

Can you use an octane booster and low octane fuel to accomplish the same effect? What if you add octane booster to high octane, at what point is octane too much?

Skirmich

^ Far easier just to mix Premium and Regular to get something in the middle... Octane boosters need a higher ratio to work properly and odds are you will always have way more fuel than booster so it will have no effect.

3.2TLc

For all the more it costs, use at least a mid grade octane fuel when filling up. Otherwise if ya insist on using the cheap low octane fuel.......alternate every other tank fill-up with the best premium grade available at half tank intervals. The octane boost additives are not worth the money or effort, IMO.

coronaman

I'm new here how do I add my car?

fsttyms1

Why? And difference you would save between regular and premium would be lost by the more costly octane booster. The ECU is tuned for 91 octane, anything above that is not going to gain you anything.

Skirmich

^^ I believe hes trying to boost 87 octane fatty so save money.

coronaman

No just wondered what would happen if you added it to 91 trying to achieve 93.

fsttyms1

Nothing other than costing you money

Skirmich

That would require some timing change by the ECU and ours don't do that so you will get nothing.. Our ECU will work with 91 and continue to work with those presets even if you add 93.


As fatty said it will only cost you more money.

Wiemert Joseph

If its your first Honda,or fourth like me,you finally got your head out of your ass and started to appreciate what Honda the premium product/acura gives you from the factory.People think oh its just like my civic,just heavier, so the hell with doing the basic services or using the correct fuel.They want to follow cosmetic trends,loud exhaust's to get attention usually negative. Grow up,enjoy driving and appreciate what you have,tommarow is definitely not promised.Honda The Power Of Dreams.