Nissan 370Z Forum - View Single Post

Gee · 12-08-2009, 11:03 PM

Yes, we are all getting over it, hence the leprachauns and such, however, my additional 20c worth.

whenever manufacturers specify the measurements of components (from wherever they get them) there is always a margin of error that needs to be stated. Nothing manufactured is ever 100% to spec. If I specify a screw of 10mm length and 5mm width it always 10mm length +/- 5 microns, or whatever. The smaller the margin of error the harder it is to meet that error, i.e. the manufacturer has to throw out those that don't mee the specs - the smaller the margim of error the higher the manufacturing costs.
Now, If I know that I cannot produce a speedo that shows less that the 'true' speed for legal reasons and I want to keep costs down then I will specify the components be made to show 'true' speed + 10% with a margin of +/- 5%. Then I am keeping my costs down and know that the speedo will (almost) never show less than the 'true' speed. i.e. it will show from 'true' + 5% to 'true' + 15% at the outside margin of error.

Somple - costs are low and I am now within my legal obligations. Hence, speedos show around 'true' + 5 - 10% on average.

math rules!

G

12-08-2009, 11:03 PM	#40 (permalink)
Gee Base Member Join Date: Nov 2009 Location: Central Coast NSW Aust. Posts: 71 Drives: 09 370Z MB M6 Rep Power: 16	Yes, we are all getting over it, hence the leprachauns and such, however, my additional 20c worth. whenever manufacturers specify the measurements of components (from wherever they get them) there is always a margin of error that needs to be stated. Nothing manufactured is ever 100% to spec. If I specify a screw of 10mm length and 5mm width it always 10mm length +/- 5 microns, or whatever. The smaller the margin of error the harder it is to meet that error, i.e. the manufacturer has to throw out those that don't mee the specs - the smaller the margim of error the higher the manufacturing costs. Now, If I know that I cannot produce a speedo that shows less that the 'true' speed for legal reasons and I want to keep costs down then I will specify the components be made to show 'true' speed + 10% with a margin of +/- 5%. Then I am keeping my costs down and know that the speedo will (almost) never show less than the 'true' speed. i.e. it will show from 'true' + 5% to 'true' + 15% at the outside margin of error. Somple - costs are low and I am now within my legal obligations. Hence, speedos show around 'true' + 5 - 10% on average. math rules! G __________________ "...'cause the only decent things that come in 2 litres are milk & orange juice"