Originally posted by G-rig
					
						
						
							
							
							
							
								
								
								
								
									View Post
								
							
						
					
				
				
			
		On a trip to Queensland in March this year we travelled around 4500km's. The average fuel usage was around 7.8L/100k's. The best i got was on purely freeway driving of course at 110kmh, returned 7.5L/100k's which really surprised me considering we had 3 adults, toddler and a boot chockablock full of luggage.


 - if the mapping is done for a specific RON (like 9
 - if the mapping is done for a specific RON (like 9 then the engine will run on that more efficiently than on the factory setting that takes a wider range of RONs into account and therefore cant run as efficiently on a specific RON.  The other possibility (and I am posturing more here) is as some have already suggested related to the change in the torque curve.  Engines are more fuel efficient under high load (ie more load at lower revs - to a point) as friction etc losses effect efficiency as revs climb.
 then the engine will run on that more efficiently than on the factory setting that takes a wider range of RONs into account and therefore cant run as efficiently on a specific RON.  The other possibility (and I am posturing more here) is as some have already suggested related to the change in the torque curve.  Engines are more fuel efficient under high load (ie more load at lower revs - to a point) as friction etc losses effect efficiency as revs climb.  , especially on boost/at higher revs then yes, you dont get to use that extra power from the same engine without using more fuel.  Not quite the holy grail of more power and better fuel economy all round, but damn close - more power when you want it and better fuel economy when you dont
, especially on boost/at higher revs then yes, you dont get to use that extra power from the same engine without using more fuel.  Not quite the holy grail of more power and better fuel economy all round, but damn close - more power when you want it and better fuel economy when you dont .
.
							
						
Comment