Anyone know how much power is lost when using regular fuel vs premium in the 4.0 V6?

[flyman767]

Agreed...I don't tow but if I did I would go with 91+.

Originally Posted by Snakeii

I've found 89 to be a good fit for everyday driving, but for towing or heavy work Id bump it up to 91+.

Id definitely be careful running anything lower then 89 in a 10:1 engine. I dont like the idea of the engine having to detune itself in order to run 87 octane.

The supercharged 89 MR2 had a manual switch in case you had to run anything but 91+. It basically does what our engines do automatically (if/when it detects pinging/knocking) and adjusts the timing. Personally, I dont like the idea of an engine having to automatically adjust when it detects pinging, if it reaches that point you are losing power and risking damage to your engine. I used the switch in the MR2 a couple of times because the stations I had to stop at didnt have premium, and noticed a loss in power and mpg.

[steve762us]

Originally Posted by Snakeii

Personally, I dont like the idea of an engine having to automatically adjust when it detects pinging, if it reaches that point you are losing power and risking damage to your engine. I used the switch in the MR2 a couple of times because the stations I had to stop at didnt have premium, and noticed a loss in power and mpg.

The trick is that the ECU can only effect a timing adjustment over a specific range...run 87, and it retards. Now add in some other unfavorable conditions...what happens when the ECU runs out of it's range?

"Knock knock..."

You might end up with enought detonation to cause damage...and it might be an ASE master tech who doesn't know about knock sensors, doing the repairs.

[flyman767]

OUCH....

Originally Posted by steve762us

You might end up with enought detonation to cause damage...and it might be an ASE master tech who doesn't know about knock sensors, doing the repairs.

[walters]

Originally Posted by steve762us

You might end up with enought detonation to cause damage...and it might be an ASE master tech who doesn't know about knock sensors, doing the repairs.

Yes, it does seem odd that a supposed master tech does not understand the simple concept that more advanced timing equals more power and more fuel economy.

[Snakeii]

I prefer to keep my cars far away any mechanic, ASE certified or not. From my experience the majority are nothing more then a wannabe with a certificate. Unfortunately I dont have a computer to plug the ECU into. As long as I keep up the scheduled maintenance and only run recommended or better fuel, lubes, etc then I'm reducing the chances of having to rely on a "certified" tech touching my vehicle. They cant even do a oil change without fracking it up, why would I want them to try to troubleshoot a problem?

Its along the same lines of computer certifications, just because someone downloads and studies brain dumps from others that have taken the tests, and end up passing doesnt mean they actually know what they are doing.

[ASE_Master-Tech]

Originally Posted by walters

Yes, it does seem odd that a supposed master tech does not understand the simple concept that more advanced timing equals more power and more fuel economy.

I will state again, please read my post completely & understand what "octane" refers to.

Engine ECU's have more than enough range to correct for fuel product differences/defficencies related to detonation. ECU's are designed to set an indicator (ie-"service/check engine" light) when conditions are "out of range" (& how did they get there if they have a very "limited" range) for a specific period of time &/or will employ a "limp" mode until the issue is repaired - or a certain amout of time elapses, &/or a pre-determined amount of re-starts occur, with no further incidents for a re-set (providing no "hard" codes are present).

Although "combustion timing" is somewhat more complex than discussed here, for simplicity sake, advancing ignition timing leans the combustion process, retarding the timing richens the combustion process. Yes, a lean combustion process will provide slightly more power (ie-all the fuel is being used to heat the available air higher causing it to expand faster) but will run hotter & is therfore more prone to detonation, & lean mis-fires do not increase you mile-per-gallon numbers.

Regarding the comments about compression ratio (ie-10:1), very few engines ever achieve the ratio that they are "bench capable" of. A 10:1 will be lucky to actually achieve a true 8:1 performance level in the real world. "Compression pressure" or "cylinder pressure" is a much more accurate way to determine how much power you can squeeze from an engine (& what you need to do to get more). When building racing engines, it's about cylinder pressure, compression ratio numbers are for shade-tree repairers & mechanic wannabes. Any real mechanic can easily make 8:1 pistons perform like 10:1 via cam choice, headflow, squish bands, etc...

My advise is to use what's recommended by those who designed & built the product.

No personal offence intended here, but if you are going to refute anothers reply, please bring your expertise along with you. Blanket comments without technical explanations do not support your objections - IMHO.

[ASE_Master-Tech]

Originally Posted by Snakeii

I prefer to keep my cars far away any mechanic, ASE certified or not. From my experience the majority are nothing more then a wannabe with a certificate. Unfortunately I dont have a computer to plug the ECU into. As long as I keep up the scheduled maintenance and only run recommended or better fuel, lubes, etc then I'm reducing the chances of having to rely on a "certified" tech touching my vehicle. They cant even do a oil change without fracking it up, why would I want them to try to troubleshoot a problem?

Its along the same lines of computer certifications, just because someone downloads and studies brain dumps from others that have taken the tests, and end up passing doesnt mean they actually know what they are doing.

How many ASE certifications do you hold that qualify you to pass judgement?
My first guess would be none.
You may frown upon the process, but it is nothing like "computer" certifications. Most of those certifications are provided by the product manufacturer (ie-MicroSoft, Cisco, SunMicrosystems, etc...). No product maker is involved in the ASE tests, so there is no interest in product marketing via certification.

Your comment is perhaps the most ignorant that I have yet to encounter on this site.

[GreenMtnMan]

Characterizing compression ratio as something used by shade tree mechanics diminishes the usefulness of the value. The only way to accurately compute cylinder pressure is to measure it, since it will vary from engine to engine and cylinder to cylinder. Compression ratio can be computed accurately on paper, since it ignores the dynamic nature of valve and ring performance, therefore it is a useful comparison of engine capabilities. Note the word "capabilities", it isn't an accurate metric of measured performance.

[walters]

Originally Posted by ASE_Master-Tech

I will state again, please read my post completely & understand what "octane" refers to.

ASE Master Tech continues with several paragraphs of obfuscating bull****.

I don't remember mentioning "octane". What I said was "it does seem odd that a supposed master tech does not understand the simple concept that more advanced timing equals more power and more fuel economy." Do you disagree with this statement?

It seems to me and others here that the reason for ECU controlled timing, utilizing a knock sensor, is to maximize performance (read power and fuel economy) by adjusting for maximum advance without knock. This allows the engine to make use of the anti-knock properties of premium fuel. Do you disagree with this statement?

[Snakeii]

Originally Posted by ASE_Master-Tech

How many ASE certifications do you hold that qualify you to pass judgement?
My first guess would be none.
You may frown upon the process, but it is nothing like "computer" certifications. Most of those certifications are provided by the product manufacturer (ie-MicroSoft, Cisco, SunMicrosystems, etc...). No product maker is involved in the ASE tests, so there is no interest in product marketing via certification.

Your comment is perhaps the most ignorant that I have yet to encounter on this site.

Gee Mr Master Techabutor, we've been through my credentials before in regards to torquing lug nuts and the like. I dont have any ASE certifications. Do I need any in order to properly maintain and work on my vehicles? NO! Go back to our previous discussion and re-read my experiences which include working on various aircraft equipment including electrical, mechanical, pneumatic, hydraulic, etc systems.

My comment is ignorant? Or is it perhaps based on my experiences I've had with so called dealer certified mechanics that dont know the difference between a supercharger and a turbocharger? Or why a manual transmission doesnt require the flushing that a automatic transmission receives? Or they dont even know how to properly fill the crankcase during a oil change, on top of that they forget to put the oil filler cap back on. Nothing like getting your MR2 home just in time to see a couple of quarts on the ground and all over the engine bay, and when you check the dipstick its STILL OVERFILLED! Should I continue on with my experiences with so called ASE certified mechanics?

As I previously stated "the majority" of ASE mechanics from my experinces are half wits. I may not know everything there is about working on my vehicles, but I at least pay attention to what I'm doing and refer to the manual for specs and other items I dont know yet. I havent done much to the Tacoma yet, but on my MR2 I had done everything from replacing brake pads, to rebuilding the supercharger, to upgrading the suspension to a coilover system, new bushings, tie rods, sway bars, wheel bearings, etc. I even learned enough of the supercharger system to modify it as well, which increased the boost by a hair at no cost.

So get off your box.

[briq4]

Just a point of interest, on the fueleconomy.gov web page, which is where the EPA mileage estimates come from, they state that the numbers they come up with on the V-6 are using regular gas. And that is what the "required" gas is for the V-6.

[flyman767]

YES, THIS HAS BEEN DISCUSSED AT LENGTH MANY TIMES BEFORE. THE TOYOTA TACOMA V6 4.0L ENGINE WILL RUN 'OPERATIONAL' WITH 87 OCTANE. I DON'T THINK YOU WILL HEAR FROM ANY CREDIBLE SOURCE SAYING SOMETHING TO THE CONTRARY. ALSO, 87 OCTANE IS NOT NECESSARY WHAT IS 'REQUIRED'. RATHER, WHAT THE MANUAL STATES: '87 OCTANE OR BETTER'. AND YES, FOR ULTIMATE PERFORMANCE 89 OCTANE+.

Originally Posted by briq4

Just a point of interest, on the fueleconomy.gov web page, which is where the EPA mileage estimates come from, they state that the numbers they come up with on the V-6 are using regular gas. And that is what the "required" gas is for the V-6.

[ASE_Master-Tech]

Originally Posted by walters

I don't remember mentioning "octane". What I said was "it does seem odd that a supposed master tech does not understand the simple concept that more advanced timing equals more power and more fuel economy." Do you disagree with this statement?

I stated previously that a lean mixture produces more power & that advancing the ignition event will produce a leaner mixture.
I will now state that lean mixtures run hotter, & are more prone to mis-fire which heats things up further. Excessive combustion chamber temperatures cause detonation (ie-knocking) so getting things too hot is counter-productive. Modern engines will "see" these changing conditions & make corrections as needed (maybe even by retarding the timing - no?)

Originally Posted by walters

It seems to me and others here that the reason for ECU controlled timing, utilizing a knock sensor, is to maximize performance (read power and fuel economy) by adjusting for maximum advance without knock. This allows the engine to make use of the anti-knock properties of premium fuel. Do you disagree with this statement?

Yes, I do disagree, the efficient operation of the engine is controlled by more than just the knock sensor. The ECU looks to acheive a stoichiometric (perfect fuel to air mix for complete combustion) efficency & it uses many input & control devices to perform this task. If 14.7:1 (at sea level) is the stoichiometric value for gasoline, your engine will squeeze the same fuel to air mixture in per stroke regardless of octane rating (so much for that economy idea). The fact that most regular fuels actually contain more heat energy (BTU's) than premiums & energy = power, with the engine controls today, modern engines won't benefit by using higher octanes than they are rated for (unless you upped your compression pressures), but your wallet will know the difference.

[ASE_Master-Tech]

Originally Posted by Snakeii

Gee Mr Master Techabutor, we've been through my credentials before in regards to torquing lug nuts and the like. I dont have any ASE certifications. Do I need any in order to properly maintain and work on my vehicles? NO! Go back to our previous discussion and re-read my experiences which include working on various aircraft equipment including electrical, mechanical, pneumatic, hydraulic, etc systems.

My comment is ignorant? Or is it perhaps based on my experiences I've had with so called dealer certified mechanics that dont know the difference between a supercharger and a turbocharger? Or why a manual transmission doesnt require the flushing that a automatic transmission receives? Or they dont even know how to properly fill the crankcase during a oil change, on top of that they forget to put the oil filler cap back on. Nothing like getting your MR2 home just in time to see a couple of quarts on the ground and all over the engine bay, and when you check the dipstick its STILL OVERFILLED! Should I continue on with my experiences with so called ASE certified mechanics?

As I previously stated "the majority" of ASE mechanics from my experinces are half wits. I may not know everything there is about working on my vehicles, but I at least pay attention to what I'm doing and refer to the manual for specs and other items I dont know yet. I havent done much to the Tacoma yet, but on my MR2 I had done everything from replacing brake pads, to rebuilding the supercharger, to upgrading the suspension to a coilover system, new bushings, tie rods, sway bars, wheel bearings, etc. I even learned enough of the supercharger system to modify it as well, which increased the boost by a hair at no cost.

So get off your box.

You seem to be confused, in one sentence you speak about "Dealer Certified" technicians & in another you speak of "ASE certified" technicians, I believe you stated that the "Dealer" was responsible for your heartaches. Dealer certifications are doled out by the product manufacterer to enhance a public image of perceived quality & promote thier product (just like Microsoft). They are only the "standard" for that particular brand.

ASE certifications are an industry wide standard. Both Manufacterer & Independent shops recognize & acknowledge these certifications. It is a voluntary certification process supported via testing fees that tests working knowledge of the operating principles & correct repair procedures as they apply to the industry & refers to no particular "Brand". It has been the industry standard for more then 30yrs.

If this testing process is so flawed, kindly explain to me why every racing association that operates in the USA, all aftermarket parts makers, & yes, even vehicle manufacterers (along with countless other organizations), support this type certification.

Because you are not employed in the motor vehicle repair industry it is diffucult for me to put any value behind your comments as they are not "professionally" based, but simply the rantings of one disgruntled patron.
There are many people with a set of wrenches that claim to be mechanics (like you). I personally would not go to a website for heavy equipment & argue about digging holes with certified operators (or argue the merits of certifications I do not hold) simply because I owned a shovel or planted a few bushes.

**please excuse me dragging this post off-topic folks, I just felt it necessary to respond to attacks of character - sorry

[Snakeii]

Originally Posted by ASE_Master-Tech

Because you are not employed in the motor vehicle repair industry it is diffucult for me to put any value behind your comments as they are not "professionally" based, but simply the rantings of one disgruntled patron.
There are many people with a set of wrenches that claim to be mechanics (like you). I personally would not go to a website for heavy equipment & argue about digging holes with certified operators (or argue the merits of certifications I do not hold) simply because I owned a shovel or planted a few bushes.

**please excuse me dragging this post off-topic folks, I just felt it necessary to respond to attacks of character - sorry

Attacking of character? All I said was the majority of mechanics I've dealt with were incompetent idiots. Thats from my experiences, and I'm not making a statement that all certified, whether by the dealer or ASE or what ever, mechanics are idiots. If they were then there would be some serious troubles for dealers and private shops. If you have a problem with my statement, pick a fight with the idiots I speak of, who are representative of so called "professional mechanics."

If anybody is attacking someones character, its you attacking me. I could really care less if you consider me a mechanic or whatever. I KNOW I went to technical school at Chanute AFB to work on the equipment, and that is all that matters to me. And after tech school, I underwent on the job training for quite some time to go from apprentice to skilled tech. The Air Force doesnt screw around with what skill level you are at, as it can lead to equipment damage, loss of life and limbs. Mechanic doesnt really apply to AGE because our job went past that, involving electronics and other systems. So before YOU attack my character and saying I dont know s**t just because I dont work in the automotive industry, do some web surfing or call up a AF recruiter and ask what the Aerospace Ground Equipment guys do. Besides, I would never want to work in the automotive industry because I hate going home everyday smelling like grease and oil. I enjoyed working on the electrical part in AGE, but I didnt like changing oil, greasing up zerks, washing the undercarriages of diesel generators and air conditioners, etc. Thus the reason why I went into computers. I dont mind working on my own rigs, occasionally, thus why I own Toyotas.