Speedometer Reading

dezzy · Post by **dezzy** » Wed Sep 27, 2006 5:01 pm

My undestanding for standard Bridgestones on an S2 is:

Front: 26psi
Rear: 27psi

That's what mine are currently set at. It's what I've been told by people on here and by MMC. My manual only gives the pressures for Yokohamas, not Bridgestones. If you want definite confirmation, give Lotus a call.

BTW, you will be seriously affecting your fuel economy with such under-inflated tyres. Get 'em pumped up asap!

james · Post by **james** » Wed Sep 27, 2006 5:19 pm

Dezzy

Thanks, I assume thats cold pressures?

mac · Post by **mac** » Wed Sep 27, 2006 5:21 pm

Yup, cold presure - but define cold

Mac

james · Post by **james** » Wed Sep 27, 2006 7:54 pm

ok, pumped up tyres to proper pressure and suddenly now all that slow speed yanking on the wheel is not required.

FFS how can MMC send out a car like this?

dr al · Post by **dr al** » Thu Sep 28, 2006 7:25 pm

my 2001 S2 is also accurate to within 1mph compared to gps.

My father in law's old volvo, though, overread by 8mph at 30!!!!!!! - now he knows why he used to piss so many folk off through town!!

A.

Blaque · Post by **Blaque** » Thu Sep 28, 2006 8:05 pm

I run Bridgstones, and when I first got the car I found it harsh, a bit "crashy" if that makes sense.

Dezzy's right with the pressures he quoted, but I'm running mine at 24.5psi at the front and 26psi at the back. I feel its not as harsh, and theres a little more grip, may only be my perception though.

dezzy · Post by **dezzy** » Thu Sep 28, 2006 11:09 pm

Sorry, should have stated that was cold pressures.

Yeah, slightly lower pressures will give a bit more grip I think, espcially in winter I believe, but I think there's a fine line where it actually becomes detrimental to reduce them more. Definitely worth experimenting with though! I'll do this once I get myself on a track!

Bear in mind though, a few PSI can make a big difference to fuel economy, so if you're a tight-@rse like me, then make sure you check them regularly. I try to check them every week, at least every fortnight. With the price of petrol these days, it might make a wee difference, and remember . . . ever penny's a prisoner!

james · Post by **james** » Thu Sep 28, 2006 11:47 pm

Dezzy

I certainly noticed the difference today going from what was 19/21 to 26/27 PSI

The car is quieter on the motorway and I now have power steering (at least thats what it feels like compared to what it was like before)

Post by **campbell** » Tue Oct 10, 2006 9:58 pm

Shug wrote:I also hear rumour (not sure of the truthfulness) that the S1 was pretty accurate up to ~80, but they changed the S2 to over-read for the same reason most manufacturers have theirs over-read as standard. El's S3 is exactly 4mph out at all speeds (according to Road Angel)

I too always thought (and felt) that the S1 speedo was pretty accurate. This is why I can cruise through a Gatso in a 50 or 70 limit and appear to be overtaking most other cars! But then it's also important to remember, no margin for error when in my Elise...unlike Lisa's Golf

Campbell

Rag_It · Post by **Rag_It** » Tue Oct 10, 2006 10:00 pm

Used to run 24 fr and 26 back on the VX with bridgies, and i found that to be best combo - get one of the halfrauds digi meters and keep it at that otherwise you will find handling characteristics wayward if you let them slip, oh and dont overinflate either!!!!

Dave

garyk220 · Post by **garyk220** » Thu Oct 12, 2006 12:48 pm

Comparing the speedo reading with the output from the wheel speed sensor, which I pick up from the OBD-II port, the speedo on my VXT is accurate within 1mph up to 60-70ish. It over-reads by 3 or 4mph at 110ish at Knockhill. And over-reads by 5mph at max speed on the autobahn a few summers ago.

alicrozier · Post by **alicrozier** » Thu Oct 12, 2006 1:03 pm

How accurate is the wheel speed sensor...???

james · Post by **james** » Fri Oct 27, 2006 12:46 pm

Ok I have cracked it (maybe

) I was sitting in the car on the phone yesterday and noticed that when the ignition is ON and the car is stationary the speed is showing at just under 10Mph. When the ignition is OFF it indicated 0Mph (obviously when stationary)

So playing with it a bit in the traffic on the M8 this morning (usual Glasgow approach) when stationary it says 10Mph, then you start to pull away and IMMEDIATELY the speed indicated builds. No lag or anything that might indicate that very low speeds arent shown.

Is this normal? I've never driven another Elise so dont know.

Novice Racer · Post by **Novice Racer** » Fri Oct 27, 2006 12:56 pm

james wrote:ok, pumped up tyres to proper pressure and suddenly now all that slow speed yanking on the wheel is not required.

FFS how can MMC send out a car like this?

That's nothing......wait till you have to ask for somthing to get fixed.....

Novice

james · Post by **james** » Tue Oct 31, 2006 1:08 pm

This problem seems to be fixed.

I posted a topic in General asking for a technical contact and Graeme at MMC actually called me yesterday after seeing it. He said it sounded like my instruments needed reset to zero becasue they can loose their calibration sometimes.

So heres how to do it.

Disable alarm immob
With the ignition key OUT and obviously the ignition OFF press AND HOLD the little black trip reset button on steering colum.

Then

Insert key and turn ignition on so that the battery lights etc are all lit.

Theres a whir and the firmware date is shown on the display for a few seconds.

Switch off ignition.

Thats it, my speedo now reads 0Mph when stationary and interestingly my rev counter now appears to read a more realistic value now (I'd never seen less than 1200 RPM shown when idling before and always though it was lumpy for an apparent 1200 RPM.)

I've not driven it yet but I fully expect this to have solved the problem.

Thanks to Graeme for phoning me so promptly (or at all actually as it was a surprise

)

Happy Lotus driver again.