Your never going to "hurt" a factory engine with a factory tune just by running 87 compared to 91. It will make a couple less hp but the computer is more than capable of reducing timing to make it safe. Also based on testing I have done premium gas will generally net better mileage even if the car only needs 87.

 

On average I drive about 8000 miles per year with an average of 16MPG.
8000/16=500 gallons X 0.20 (extra cost of premium)=$100 per year.
Amount that I've spent on test equipment would easily offset extra cost for a few years. If money were a concern I wouldn't even bother. Most of the cars that I've owed required premium as well (1994 Lexus LS400, 1996 Lexus LS400, 1999 Lexus LS400) so I've been reaching for 91 most of my life.

Now some relevant info:

I've contacted Innova for explanation of the test and this is what I was told: " ...3160 series tools have the ability to retrieve the Spark Advance on Cylinder number 1, but only in the Freeze Frame Data. It will not simply read the advance at will."
I guess what it means that if cylinder #1 is last in a cycle I will lose one data point. So when test reported 2 data points out of 60 means that it could have been 3 due to the sequence. Chance of that happening is 1:6.

Back to the test equipment. I also used android plug in which reported similar results (which cost me only $30) but without fancy bs. Difference is if there was no timing adj. detected it wouldn't provide any date except saying that no detonation was detected. Unfortunately I cannot run them simultaneously but only one after another.

Disclaimer: In order to avoid being accused of plagiarizing somebody else knowledge as have happened in the recent past from now on I will use " " to avoid same confusion.

 

Is this really happening again?

 

Don't act innocent. You got caught. Take it like a man and move on. You want to start this thing up again I'll be glad to copy and paste what you posted where you blatantly plagiarized and got caught. We can take a vote but I promise you're not going to like the results.

 

^ he is- read his disclaimer.

 

If anyone has an interest to go through my dirty laundry here is a link

https://acurazine.com/forums/3g-tl-2004-2008-93/regular-87-unleaded-ok-use-905959/

and if someone think that nfnsquared is on my side think again. Here is a link to a thread where we where throwing dirty socks at each other

https://acurazine.com/forums/3g-tl-2004-2008-93/massive-problem-safelite-windshield-replacement-901230/

I'll try to keep it on topic as much as I can.

Edit: By the way I think I lost both battles. I will try to be more accurate in expressing myself. English is not my first language.

 

I always put 89 in mine

 

Sorry I missed a legitimate inquiry:

Outside temperature in city of Irvine, CA during test was 72 Fahrenheit. Scanner reported 2 incidents out of 60 under stress in 5th gear. Speed was 40MPH gear was locked in 5th and pedal to the metal. I guess most with knowledge would call it WOT by I might be wrong.
Both data points show -0.5

Both fill ups were at the same Chevron station.

Thanks for asking.

About me: I am a 40 years old, male, CPA, auditor at heart and live by definition "Trust but verify" <-- I think some one said it before so I used " " just to be on a safe side.

 

It usually takes a few tankfuls of gas for the computer to fully adjust to the difference in octane. Be a better test to drive 1000 miles with each type of gas to really see what the effect is.

 

It is relatively cool day today 65 degrees.
Before you will think that I am totally stupid some streets in Irvine have a posted speed limit of 55.

I weight about 190 lb and still have 3/4 of a tank of 87.
From stand still (red light) at WOT usually get between one and two data points with time adj.
Usually at the speed above 65MPH and RPMs above 4600
Something like:
timing was adjusted at 66MPH at 4650RPM adj -1.0
timing was adjusted at 74MPH at 5475RPM adj -1.0
Since scanner reads cylinder #1 it looks like it start to adj. timing above 4.6K RPMs and keeps adj. until up shift.

One of the data point with RPMs above 6K was reading timing adj -4.5

But if it was a rolling start lets say I begin acceleration at 10MPH tester wouldn't read any adj. do not know why. I will run similar test later with 91.

So far it looks like I have to get way out of my normal driving habits to see any timing adj.

If anyone has any suggestions/recommendations/ideas how to run a test let me know.
My lunch hour is much more interesting now.

 

Total BS as far as knock detection/timing retard is concerned. If the knock detector goes off, the ECU is going to pull timing immediately. It's not going to wait 2 tank fulls before doing so....

 

Use premium I had motor knock & lag with regular/plus; premium no problems...people opened their engines after 100k's mi. Claims of engine being clean like new...

Use good oil; use good gas & you'll be good ...

 

I fully agree with this. Within the top tier fuels, the premium usually has more detergents and additives in general. Of course, that's up to the maker but it's usually the case. My intake bowl area and valves were incredibly clean at 113,000 miles. They weren't just carbon free, they looked 100% brand new, no evidence the engine had ever been started. I've owned it since it had 8 miles on it and it's always had premium in either Shell or Chevron (due to their good but very different additive packs that I figured would cover every aspect of cleanliness when alternated), with a few tanks of off brand regular due to poor planning on my part over its lifetime.

 

I highly suggest learning you scanner forwards and backwards with no assumptions. This is the only way to get valid test results. I'll bring the Snap-On one of these weekends and hook it up to your car if you want.

KR is going to get significantly worse as temps climb. Most of my testing was done on 100 degree days and there's a good amount of KR even on 91 under some conditions.

You have to simulate real world conditions. Driving it for a few minutes under varying throttle is not the way to do it. Drive it in normal stop and go and do so for a good 30-45 minutes to get a taste of what heat soak does for KR. While coolant might hit full temp in a few minutes, full core temp, heat saturation is not reached for a good 30 minutes or even more. Full throttle isn't necessarily where you will find the most knock. In mine I usually got the most KR at moderate throttle and low rpm.

Find out how your scanner displays KR, not how you think it displays KR. Some are much different than you would think and the logical way isn't necessarily the right way. Make sure a readout of -1.5 is actually 1.5 degrees deviation from the timing map. Am I understanding you right that you think it's only showing what's happening in one cylinder? I can tell you something is wrong if that's the case.

A little KR on the shifts is fine and somewhat normal.

KR usually gets worse in the higher gears depending on how aggressive the factory map is. If you're getting knock in first gear besides initial throttle tip in (which is also kind of normal) broken mounts, something causing metal to metal contact is probably the cause of false knock. Tire spin even with TC disabled can cause real and false knock.

The TCS kicking in can cause false knock as well.

If you have knock only under certain conditions and you think it's false knock, a tank of 100 octane will sort out false from real knock. All of this needs to be investigated before drawing any conclusions.

 

One of the weaknesses of the tester that I use is that it reads data from cylinder #1 only.

I am not trying to alter anything. I take my kid to kinder garden about 1.5 miles, go to work about 1.5 mile to get to freeway and about 2.5 miles on a freeway, go to lunch 1-2 miles, sometimes go home 4.5 miles. My morning commute of 5.5- 6 miles and spending 5 minutes to drop my kid off takes about 25 minutes. Thant is why average MPH on each tank of gas is very consistent 20MPH 16MPG according to MID. So my commute is very real.

Scanner will read a knock on a start up only if there is a short period of time (less than 5 min) between shut off and restart on a hot engine. I do not remember hearing any noises using 91 but I didn't pay as much attention before. Will test once fill up with 91.

It will also read timing adj. under stress such as if I hold higher gear at lower RPMs under normal driving conditions AT would just down shift.

I will repeat test with 87 and 91 once temperatures get a little hotter.

 

I'm trying to help so don't take this the wrong way. Being able to see only one cylinder out of 6 is close to useless. It sounds like you can't see it in real time but in freeze frame mode. Air distribution is not even between cylinders and you can have one that gets less air that never knocks where the ones that get more air knock.

Knock on startup is fine.

You need to get a better scanner because your results are going to mislead people. I'm not trying to discourage you, I'm trying to make sure the data is accurate which in this case there's no way it can be accepted as accurate or useful.

 

I was thinking since there is only one knock sensor it will not meter much if it pull timing based on the knock in any other cylinder but if ECU corrects timing to each cylinder independently then yes results will not be accurate and misleading. But at the same time if all cylinders have fairly equal wear and tear results will be good enough for recreational purposes. Again I am not looking to prove or disprove any theory I am doing it purely for fun.

 

Right. If it pulls individual cylinders the test won't show anything useful. If it retards all cylinders as a unit the test can be useful. I don't know how the TL does it but with individual knock monitoring vs batch monitoring only being a software update, I would guess it's individual although Honda tends to do things differently sometimes.

Wear and tear doesn't have anything to do with knock unless it's causing oil consumption or compression loss. What does matter is AFR and unfortunately it's not 100% consistent from cylinder to cylinder. The main contributor is uneven airflow distribution by the intake manifold. Secondary is slight differences in injector flow and sometimes pressure drop across the fuel rail. Then there are the minor differences such as some cylinders running hotter than others due to coolant flow and even EGR distribution.

Basically some cylinders are more likely and will detonate more than others.

One cool thing you could do that I forgot to do is to disable the EGR and watch knock in normal driving. Normally it should knock more but I think once the ECU in these cars see an EGR failure, they go to a no EGR timing map. It would be nice to know for sure.

Almost forgot about high load and low rpm. I didn't mean to shift it manually and do something you wouldn't do in day to day operation. What I meant was to drive normally but when it shifts to 4th at light throttle and you decide to accelerate a little harder but not enough for a downshift, that's when a lot of the knock occurs.

The most knock I saw was a 20-30 minute drive, stop to eat for 20 minutes and get back on the road. Driving after sitting for a short amount of time made it knock a lot.

Even with monitoring one cylinder it will be interesting to see the difference in mild and hot weather. Mine is good until it gets above 85 degrees.

 

lol *eyes tearing*

 

I don't know, but I highly doubt the stock TL ECU is capable/mapped of/for individual cylinder timing adjustment. Assuming that is true, then the scanner only needs to read one cylinder (any cylinder) to detect timing retard/advance...

 

When knock is mentioned by some, are you saying that this is something you hear?

I have heard knocking in previous vehicles so I know what that sounded like and want to make sure that I am not missing something.

I have never heard knock using regular with TL, including on hills with just enough throttle to keep from down shifting and temperatures above 90/95F. This is at 5500 ft elevation and fuel at normal 85 octane for regular at this elevation.

Clearly others are experiencing the knock so I am trying to understand why I am not hearing it!!! Also performance, shifting, idle, stop for short periods of time and driving again, engine cold start, manually shifting AT as early as possible under light throttle to keep from downshifting... have no perceivable difference with regular/premium.

My wife is very particular and notices the smallest differences, and I make a fuel change over a few tanks and ask her has she noticed any changes, heard ping (she knows what this is), if there is a difference between last few tanks of fuel and previous three...then switch back and ask her if she can tell any difference (not letting her know which fuel is in the tank).

I'm just trying to understand...Could this be due to the elevation and even at 85 octane???

 

I say knock because timing is adjusted based on sensitivity of a knock sensor not because I can hear it. I've never hear my TL knocking. I am sure most of us heard that noise of a overheated vehicle "tsock tsock tsock tsock....."


Exactly my though process.
Another thing to consider, company that made tester went through a trouble to develop interface to read knock data from ECU and then limit it just to one cylinder.

 

On my last fill up with 87 I've driven 230 Miles after filling with 15.105 gallons = 15.23 MPG

Here is a summary:
During this test MID went up by 1 MPG from 16MPG to 17MPG average MPH is 20 according to MID.

First fill up 233/14.4 = 16.18 MPG
Second 218/14.5 = 15.03 MPG
Third 230/15.1=15.23 MPG

On my last fill up with 91 my stats were 220/14.9 = 14.77 MPG

During last fill up it got very hot and I was using A/C for about a week.

When temperature in Irvine was 88 Fahrenheit scanner didn't report any timing adjustments under normal conditions. But when I lock 3,4 or 5th gear preventing downshifting and step to the floor that is when scanner would report timing adjustment by 0.5 on 2-3 cycles. Once outside temperatures will get above 80 I will test using 91.

PS. My wife's car Lexus RX 330 after 3 consistent fill ups with 91 lost about 20 miles of range on each tank, but engine sounds and fills much different with 91 I mean good different like it got a boost of energy. If I'll get a chance I will run scanner on her car just to see if my natural sense/feeling will be confirmed by digital device. I've never noticed such differences with TL. And if Acura did any improvements to knock sensor during production years then there could be noticeable differences as well. I weight about 190lb and was the only person in the car during all tests I am sure that caring any load and passengers would make results different.

 

Do you drive your car particularly hard? Or just a lot of heavy rush hour traffic? I know my Accord weighs a few hundred pounds less and has a slightly smaller V6 but even with horrible light timing here (as in you drive from red light to red light most of the time), I get a pretty consistent 22.5 mpg city (with some freeway) in the Dallas area. Been warm enough the a/c is on regularly (well, at least until this week) and I don't drive like an old lady.

I do run 93 octane, FWIW. The RSX wheels I have weigh several pounds less than the OEM wheels too.

Looking through the mileage log my Dad kept (I bought my car from him), his average in town was closer to 20 mpg even and I know he used 87 octane regular. He keeps pretty meticulous records too, which is probably why I've continued to log every tank of gas. Between his records and mine, there is 152,700 miles worth of fill-ups logged! We both did the math on the mileage too, didn't use the trip computer, even though it is usually within 1 mpg either way.

 

I was driving 4 cylinder camry for a few months before getting TL and my MPG was around 20MPG for same commute.