what mileage are you usually getting on your lc? I am curious because there was a time I filled up at a new station with a different type of premium fuel and upon driving off the mileage shot up to around 9.5kms to a liter whereas previously it was only around 8. What is noticeable was after only 1/4 tankful everthing started getting smooth and quiet running.. what happened and how was it that the computer immediately noticed the new fuel quality? How does the computer know that?
How does fuel quality affect the computer mileage indicator?
- Thread starter slicky rick
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If you were in the US, I'd say going from ~10% Ethanol (standard summer gas) to ethanol free would show a change like that, albeit not that large. Not sure where you are in Asia, but is there a regulated fuel and options to buy other fuels?
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We have the regular diesel fuel and premium diesel fuel... and for the premium diesel we have two major brands.. what I did was simply to change premium diesel brand
No diesels, here, but US diesel fuel has % of biofuel on the label at the pump. Maybe there's a difference between those diesel brands? Someone more experienced in diesel will have to chime in, I'm just guessing at this point......
The way I understand it, Toyota has decided to allow the software (algorithms) to take raw data, in real time, to calibrate and run the ECUs so there is no actual "tune", more like running within a "constant variable" depending on readings from sensors - pre-drivetrain, post drivetrain, and everything in the middle...
With regards to gasoline engines, one of the things I read that made an impression on me was the DAP tuners claim that "These engines pull 8-12 degrees of timing due to knock retard on 87 oct, 6-10 deg on 89oct, 2-6 deg on 91oct, and 0-2deg on 93oct. That is on a completely stock truck with factory tune." Wow! (if that's true).
Does the same logic apply to diesel? IDK. What is the difference between regular and premium diesel?
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With regards to gasoline engines, one of the things I read that made an impression on me was the DAP tuners claim that "These engines pull 8-12 degrees of timing due to knock retard on 87 oct, 6-10 deg on 89oct, 2-6 deg on 91oct, and 0-2deg on 93oct. That is on a completely stock truck with factory tune." Wow! (if that's true).
Does the same logic apply to diesel? IDK. What is the difference between regular and premium diesel?
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^ Somewhat true. The engine ECU maps have a base tune. The base tunes are very optimal with complex math models to know what the engine wants given atmospheric conditions via the MAF, engine temp, load, etc. It further relies on sensors dedicated to feedback loops (O2 sensors, knock sensors), to "trim" the tune as a result of conditions/fuel quality/engine health, etc.
For the OP, must be a case of bad gas in the prior batch. Modern vehicles can quickly compensate for fuel quality with the feedback sensors.
No way. This is far overstating the case, or dramatizing the variables. Stock ignition maps do not "ride the knock threshold" in this manner, less they produce severe knock. A vehicle tuned for 87 octane, especially one like the tundra, won't have such aggressive maps. Knock, even minor knock over time, has severe repercussions to durability, emissions, and engine output. I tune Porsches, which has even more maps for fuel octane, yet doesn't have that degree of timing aggressiveness. No way Toyota, with their conservative tunes look like that. If that were the case, companies like D.A.P could never make more power. They are taking advantage of the margin Toyota has left on the table.
For the OP, must be a case of bad gas in the prior batch. Modern vehicles can quickly compensate for fuel quality with the feedback sensors.
No way. This is far overstating the case, or dramatizing the variables. Stock ignition maps do not "ride the knock threshold" in this manner, less they produce severe knock. A vehicle tuned for 87 octane, especially one like the tundra, won't have such aggressive maps. Knock, even minor knock over time, has severe repercussions to durability, emissions, and engine output. I tune Porsches, which has even more maps for fuel octane, yet doesn't have that degree of timing aggressiveness. No way Toyota, with their conservative tunes look like that. If that were the case, companies like D.A.P could never make more power. They are taking advantage of the margin Toyota has left on the table.
I started experimenting with low (87, regular) vs high (93, premium) octane after reading that and few other things.
Will it run perfectly fine and reliably on 87? Yes.
Will it run better on higher octane? Probably.
Based on my experience so far these trucks run better, or way better, on 93 octane, especially under heavy load (like pulling a boat). the differences I observe most clearly are in shift points (holding gears longer before downshifting) and pulling power at low RPMs (under 2,000) at highway speeds. Also, just general - engine seems to be running and idling smoother.
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Will it run perfectly fine and reliably on 87? Yes.
Will it run better on higher octane? Probably.
Based on my experience so far these trucks run better, or way better, on 93 octane, especially under heavy load (like pulling a boat). the differences I observe most clearly are in shift points (holding gears longer before downshifting) and pulling power at low RPMs (under 2,000) at highway speeds. Also, just general - engine seems to be running and idling smoother.
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