I've been reading through this thread and others on fuel consumption trying to find answers to my own higher then usual fuel consumption problems. I'm cleaning the MAF sensor today to see if that helps.
What's caught my interest is the discussion around octane ratings and how the engine management system adjusts the ignition.
For reference on how this operates see http://www.lcool.org/technical/prado...tane_fuel.html
I'm running my 120 Prado on LPG. Now LPG has an Octane rating of around 108-110. If you use a high octane fuel the engine management system will advance the ignition to suit over 3000-5000km, at which point you should be getting more torque and improved fuel consumption. It sounds like if you then run a tank of 91 Octane fuel through, the knock sensors will trigger the engine management system to retard the ignition to suit, and it will take another 3000-5000 km to advance the ignition again if you go back to 98 Octane fuel.
My Prado starts on petrol and switches to LPG after about 1km. I do most of my Ks on LPG. I fill my petrol tank with standard 91 Octane unleaded. This has got me thinking I'm doing myself a disservice. Maybe I should always fill the petrol with 98 octane as this will help the engine management system to advance the ignition to better suit the high octane petrol and LPG. The ignition would at least be advanced to suit the 98 octane petrol, which should also be an improvement for the LPG hopefully giving me more Ks out of each tank of gas.
Does anyone more knowledgable on this have a considered view?
I'm going to switch to Premium unleaded to test this out and see if my LPG consumption improves.
What's caught my interest is the discussion around octane ratings and how the engine management system adjusts the ignition.
For reference on how this operates see http://www.lcool.org/technical/prado...tane_fuel.html
I'm running my 120 Prado on LPG. Now LPG has an Octane rating of around 108-110. If you use a high octane fuel the engine management system will advance the ignition to suit over 3000-5000km, at which point you should be getting more torque and improved fuel consumption. It sounds like if you then run a tank of 91 Octane fuel through, the knock sensors will trigger the engine management system to retard the ignition to suit, and it will take another 3000-5000 km to advance the ignition again if you go back to 98 Octane fuel.
My Prado starts on petrol and switches to LPG after about 1km. I do most of my Ks on LPG. I fill my petrol tank with standard 91 Octane unleaded. This has got me thinking I'm doing myself a disservice. Maybe I should always fill the petrol with 98 octane as this will help the engine management system to advance the ignition to better suit the high octane petrol and LPG. The ignition would at least be advanced to suit the 98 octane petrol, which should also be an improvement for the LPG hopefully giving me more Ks out of each tank of gas.
Does anyone more knowledgable on this have a considered view?
I'm going to switch to Premium unleaded to test this out and see if my LPG consumption improves.
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