engines CC vs Litres

[Torquen]

Anyone know how close does the cubic capicty of an engine need to be befor they can call it a cerain figure, eg holdens 6.0L engine has 5967cc but is called a 6.0L engine. cause technincaly it dosnt hold 6.0L so shouldnt they have called it a 5.9L. also why wouldt they just make it 6000cc.

[eurekamad94]

they just round it off to the nearest hundred it is technicly a 5.9

[nicko]

isnt 5967 closer to 6000 though? if its rounded to nearest 100 then it would be 6000. so 6L is correct

[commsirac]

Basically, they'll round them off to suit their marketing ploy......especially if another manufacturer has a motor of similar capacity, they might want it to be the same or just slightly different, ie 350chev and the 351 Ford, not suggesting that the rounding has been manipulated here. There are rules about how to round off numbers in the sciences and finance, but they dont have to abide by that.

Basic rule: if rounding to a lower no. of significant figures, the last digit increases by 1 if the number on its right(before rounding) is 5 or more, stays the same if less than 5
if rounding the following to 2 digits, then 6.84 becomes 6.8 and 6.86 becomes 6.9


In an engine example, if the most accurate capacity given is 5.9499L, then to 2 significant figures it would be correct to write that as 5.9L not 6.0L, but if written to one sig fig would be also correct to write it as 6L, which the manufacturer might choose to do for obvious reasons.

Holden calling the 5967cc 6.0L, thats fine, that is the correct way of doing it.

Why dont they design motors to give nearest volumes to the exact cm^3(besides the holden motors being derivatives of the US which is imperial), they do, when they put all the design parameters together......and dare I say it the computer spits out numbers for optimum stroke bore etc, with the given valve timing etc, then they go with that regardless of whether it ends in 000 (in cc or ci)or not.