he means the last 2 or 3 leds on the fuel guage don't light up

Yes, I know (please read carefully)

Dammit. I knew I screwed up... I've been using carrots instead of cheese.



Correct you are! Measurements are based on new tyres only, so this science can never be 100%.



Here's another question...Where does all the worn off rubber go as you never see piles of rubber dust on the side of the road? The wind? We breath it in? I dunno.

You do see piles of it on the side of the race track. On the street the wear is so low that the deposits aren't typically measurable.

My biggest issue with reading over the actual speed is that it encourages speeding. We all know that 100 is not 100 so we get used to doing more. It's hard to do 108, so we settle for 110, which is actually a couple of Ks over - assuming 8%. Then you start getting complacent about exceeding the speed limit and the limits don't mean much any more. It's OK to do 70 in a 60 zone but that's even more over the limit.
If the speedo read what I was actually doing, I'd have a hard limit - the speed limit. At the moment, I just don't care that I'm going to fast because the speedo always reads way to high.

My 0.018USD worth.

I just think of it as a way to avoid speeding fines. I usually just cruise at the 100 mark, but I'll go up to 105 sometimes which is really about 96-97kph and sit there. I feel like i'm speeding but not.... we all win.

I have to agree with you there BluZ, I take less notice of the speedo as it appears so far out, and usually settle on what feels right especially on the highway. I know it's not the right thing to do, but I was wondering why all and sundry were overtaking me when I picked the car up from Sydney.

I think if the speedo is 9% out like that it makes you 'estimate' what speed you are doing which isn't very safe. I'd rather it be accurate. We aren't going to just sit on the highway doing 91km/h when the speedo says 100km, we'll be guessing all the time. If the speedo says 100km/h and you are doing just 91km/h then it makes a big difference over a long distance trip. I'm worried one day i'll get a ticket for being a few k over because my speed estimate wasn't correct. I used to hear about other makes and models having their speedo out by that much and used to think 'how crazy is that'. I never expected the Z to have the same issue. Is there a way it can be adjusted in a service?

This issue affects most makes of cars and I now reckon they do it for safety reasons rather than a miscalculation.

http://www.e90post.com/forums/showthread.php?t=327056
http://www.honestjohn.co.uk/forum/po...ex.htm?t=79433

They want us to drive slower and the menu in the ECU to change the correction factor will be set in the factory and hidden....maybe even from the dealer service?

Although as said, this safety theory goes out the window as everyone will speed to compensate for the inaccuracy...

I’m over this topic. :icon14:

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

Does this mean all the 0-100km times in reviews for the Z are incorrect and it's really more like 0-91km?

No. All those tests are performed with high-end testing equipment such as optical accelerometer. What the car actually reads on the speedometer is irrelevant.

A problem I had that has since been rectified -

Less than a week after picking the car I noticed one morning that the bonnet was not sitting flush with the bodywork at the front of the car. It was skewed to one side, higher on the passenger side and lower on the driver's side.

After a bit of fiddling I suspected that it was the bonnet stops that had perhaps moved around slightly. It was at the time of the first 'free' check and the dealer confirmed that the bonnet stops. See pic.

My usual technique for closing bonnets ever since I can remember is to lower the bonnet to within 6 inches of the body and let it drop to close. I know that it was sitting perfectly flush when I picked it up and I was the only person ever to open/close the bonnet.

I thought that maybe as the bonnet is aluminium and much lighter than the usual steel bonnet that maybe this technique was not a good thing. Ever since I have been lowering the bonnet to sit againt the bodywork then gently using each hand at either end of the bonnet (driver amd passengers side) to gently push it closed. The aluminium flexes a little (as it want to do) and I hav'ent had the problem since.

Anyone else noticed problems with closing the bonnet?

G

"No. All those tests are performed with high-end testing equipment such as optical accelerometer. What the car actually reads on the speedometer is irrelevant."
-------------------------

Exzarachy - and you'll find that that equipment that is used is horrendously expensive.
Part of the reason being that it is designed to be accurate to within probably 1/20 of 1% or less.

To make it worse, in the real world, usually these things are not a linear progression. Its more like a logarithmic or exponential scale. Twice as accurate is a *lot* more than twice as expensive, and so forth.

Well a 5-lb chunk of it hit my motorcycle helmet once while I was traveling down I-95. Always wear a helmet. :tup: