3.5 V6 Atkinson Cycle engine and the gas grade parade extravaganza...

I don't know how many miles it takes, but the ECU needs time to adjust to whatever changes you have made. It doesn't just change at the flick of a switch.

 

Dam I can't believe all the people saying they didn't feel a change in Butt Dyno.... ya'll must be Autos!
My very impartial Butt Dyno tells me at least plus 55 hp on Premium 93.. serously though it revs out much much smoother and takes at least .01 second off my 0-60.

 

Run the lowest octane you can get away with.
Higher octane just burns slower that's it, no magic.
If it runs better use it if not run 87.
My truck runs best with 87 ( but I have a tuner and a 2010 4.0)
and stock it like a 50/50 mix of 87 and 93. mid grade just doesn't run as good.

The tuners are making the most power with E85 but our computers are set from the factory so just mix what runs the best.
Maybe add some premium when towing ect.

 

Either your math is fu $cD or your premium gas is insanely cheap... here gas is approximately 20 cents a liter or say 75 cents a gallon more expensive.... teach me how this works to be 5 bux month !!! I want!

 

So I have a question for all of you 87 octane nut swingers. Since octane numbers don't matter according to most of you, then why is it when I run 100 octane unleaded thru my 600rr, I get better hp numbers than when I run 87 octane? and when I run 91 octane thru my bike, I still get better numbers than when I run 87 octane?

 

Is that a sports bike engine? Not exactly apples to apples here. Many variables at play, but they have to do with such a low CC, high CR, very high HP/L due to high revving nature, relatively low engine load due to very light weight, running a lot of advance on timing, and PCM programmed to take advantage of higher octane based on available knock sensor, etc etc.

 

Depends on the engine build and what the difference in HP numbers are. I don't know a great deal about how sport bike engines are built as far as standard CRs and type of gas used.

I would think that being a little light weight sport bike, you can much more easily get away with running a higher compression engine with lower octane and not get detonation. I'd kind of think that the window for detonation is much wider than for a 4500lb vehicle. That extra weight is resistance which can push the engine into spark knock. Also, they HP numbers would need to show significant over several tests.

BTW, I'm not a 87 octane nut swinger. I'm more of a use the right tool for the job kinda guy. If someone does a real test to isolate all the variables and shows that running 93 octane is better in the Taco, I'll take it. I haven't seen that yet. Mostly butt dynos and 1 tank trials which ain't enough to get it right.

 

I figured you would use the sportbike engine excuse. the fact of the matter is that octane matters. the higher the octane, the more resistant to detonation the fuel is. What does this mean for car engines? it means that the fuel will ignite while the piston is on the down swing whereas with lesser octane fuels, it could possibly ignite while the piston is still moving upwards at the end of its cycle. What does this mean? Well, it makes for a more efficient use of fuel since all of the ignition is now being used to force the piston in a downward motion vs. fighting the top of the cycle of the piston before it starts its downward motion. What happens when your engine is running more efficiently? better fuel mileage and better tq and hp numbers. but hey, what do I know? Im not an engineer, im just public employee. take the information for what you think its worth.

 

What you are saying is almost correct. The main thing you left out is that the engines are generally optimized for the type of fuel listed in the manual. Going up in octane alone doesn't make more power..... if you go too far, and the engine is set up for 87, you will actually loose power because you didn't start burning until the downward travel of the piston and you didn't take advantage of the compression at TDC..... you will burn less, make less power, and increase unburned hydrocarbons.


IMO, and engine is an engine.... they are all the same.... the details are what makes them different. If your sport bike makes more power on 93 vs 87, there is a reason it does. It was built for it. It doesn't mean it won't run on the cheap gas.... the vehicle's light weight, aluminum heads, computer, and cooling system will help it when you run lower octane. I've owned cars that specifically said to run 93 for optimum performance, but you could run 87 if you needed too. Those engines were designed for it. This manual for the taco says to run at least 87..... not run 93 unless you need to run 87.

 

Heres what you do. Fill up exclusively with premium for a year at the same station or chain of stations, same pumps if possible, same time of day, and same day of the month (as close as you can to it at least). Track your mileage with a GPS or equivalent and receipts from your fill up. Then do the same thing for another year with regular. You also have to keep same engine parameters and state of maintenance as best you can.

Then compare after two years. Doing it for a whole year will show you effects of temperature and any blend switches. If the mpg change is > than the price difference between regular and premium, then switch over. I did this test before on a different vehicle and found if the price difference was > 5% (somewhere north of ~$3.50/gal) it was worth it to switch to premium.

Oh and avoid midgrade. Its probably mostly regular with the bare minimum premium mixed in per regulations (at best its 50/50 ).

 

Says the guy who owns a car with a rotary engine........lets not get started on those things and their awesome apex seals.

 

Be careful what you ask for....one day there might be a diesel Taco that will run on jet fuel......until then, I'm happy with 100 octane low lead av-gas.

 

In Texas we have the 85 87 89 92 93.

I have tried all but 85.

Shell gas has been the best by far, but i am still leaning toward the 93, it runs great and i get better gas mileage.

With the wind blowing all the time this time of year that takes mpg out the window and i will try the gas treatment list in this thread i read its better than lucas.

NOTE: i dont believe for a minute its always the octane they say it is...I Know fuel haulers and i will leave at that!!

 

Octane does matter, in a certain way. In other ways, it doesn't matter. This is a matter of science, there's really no debate about how octane affects power output, perceived "smoothness", fuel economy, or whatever other nonsense old wives tales are floating around out there. Octane is simply a rating system for the ability of the fuel to resist detonation by heat/pressure, rather than being ignited. Note that "octane" is, generally, used as shorthand for "octane rating" - otherwise, octane is actually a chemical compound that's added to gasoline. The more octane you add, the higher the octane rating. 87 Octane fuel has a certain amount of octane, 91 Octane fuel has a certain amount, etc. If you understand the basics of how an engine and EFI work, it should be fairly obvious what effects this may and may not have.

The reason octane matters in your CBR is because that's a high revving, high compression engine with software designed to take full advantage of the octane rating. It will advance timing until it detects some predetonation, then back off. Most modern high performance engines will do this. It's not great for longevity but it guarantees you the maximum power output the fuel you're using is capable of. In something like a small displacement 4 cylinder, the extra timing you get out of 100 octane might mean 5-10 horsepower. That's imperceptible in a 2 ton car but on a 400lb sportbike, I'm sure you notice it. I don't write code for Toyota but I'm confident that the Tacoma's engine doesn't advance timing in the same way. They're concerned about durability, not an extra 10 horsepower, so they want to stay far away from predetonation. A relatively new, stock modern engine, built for economy and durability, is not going to sporadically predetonate if you use the recommended octane. They are mapped very conservatively to account for fluctuation in fuel quality.

Aside from this, for all intents, octane rating has no perceptible effects. There is no way this can result in better fuel economy, a smoother ride, or anything like that. If you've experienced something like this, it's purely your perception. That's not to say, necessarily, that you should stop putting 93 Octane fuel in your truck if you perceive an improvement. After all, perception is important to your mental health

A few other notes -

Ethanol: Ethanol in your gasoline is not going to destroy your truck. It's not going to melt your fuel lines. The only downside to having a bit of ethanol in your gasoline is that you may see a tiny decrease in fuel economy because ethanol has a lower BTU rating. I do mean tiny, though, for something like 10% ethanol. Less than 1 MPG. The difference between pure 93 Octane and pure E85 ethanol fuel in my 800hp Mustang was about 5 MPG. Tree hugging aside, the benefits of ethanol greatly outweigh this. As ethanol is a form of alcohol, it is a solvent and has been demonstrated to do a great job cleaning carbon deposits from the intake valves and runners (assuming port injection). It also evaporates very easily which results in a cooler intake air charge, which results in a cooler engine overall, which is a good thing. Ever notice rubbing alcohol makes your finger feel cold? Same principle at work there.

Detergents: Detergents are the additives in gasoline that contribute to the cleaning properties, the stability, and consistency of the gasoline. Every gasoline company has their own proprietary blend of detergents. If you really want to go the extra mile (ha!) to be friendly to your engine, instead of spending that extra money on higher octane fuel, spend it on the same octane at a better gas station. There is now a certification that says a brand's detergent blend is exceptional, it's called Top Tier. It's worth noting that when the certification came out, QuikTrip and Chevron's detergents were already meeting the requirements. Shell and Conoco Phillips quickly followed suit, and now almost all brands have it, but I'll always trust QT and Chevron more since they were already doing it before someone started handing out gold stars for it.

Hope this helps!

 

thnx dsmdylan! that does help let get on the horn with some buddies that work in the oil and gas bizz.

 

This is pretty hardcore.

 

Well that's some awesome info! I'm gonna stick with 89 cause... I have strong feelings for it... And my truck too.

 

WTF is a manual??? Oh, you mean that book thing I tossed when I drove me truck off the lot... People read that?

I kid.... For what's it worth, I've put 93 octane since my first fill up, and I'm currently at 5,500 miles. I've experienced no problems or issues... I run it because I've always run it, and because I don't mind paying the ¢15 - ¢20 difference. If anything, it's just peice of mind; i.e. if 87 is the "minimum", then I want the maximum... at least insofar as is readily available in my state. Also, add a bottle of Royal Purple Max Clean every oil change (5k) to keep the injectors clean, and everything running smoothly.

But this is just the kind of person I am... I just changed my oil at 5k instead of 10k, as the manual suggest, and put in Amsoil Signature, which is guaranteed for 25k miles or 1 year, but I will continue to change every 5k - 6k miles.

 

Knucklegrumble you should run whatever you feel is better in your truck. I was just trying to make a point that if you feel that 89 is better, there might be a reason whereas some guys were trying to tell you its in your head.

Look, I'm not trying to say I'm smarter or know more about octane, but my experience has shown that even engines that aren't high compression often benefit from a higher octane. Besides, if you think I run 100 oct. just because of the power my head seems to think it is gaining, you are looking past the fact that my valves are cleaner and pistons don't have as much carbon build up on them either. Not talking about my bike here, talking about my Civic.

Regardless what everyone thinks, if you feel you are gaining anything from running a different octane than what is recommended, you should run it. nobody knows your vehicle better than you. Every vehicle is different even though they are the same.

 

There are a few gas stations here that sell 100 octane unleaded fuel at the pump. those same gas stations sell 104 and 114 in 5 gallon cans and I'm sure just like your area, there are petroleum businesses that sell 118 and above if you know where to go. Otherwise, here in Nevada, most gas stations have 87, 89 and 91. What I miss are the days when you could get regular gas for 99 cents.