[Intrepid]

Way to go SpeedOmania...
Where r the videos... sure wanna c em...

GTO... The 5 speed Mpfi M800 is just phenomenal.... shes a darling on the road... with a loads of power for an 800cc engine...
But r u serious bout running outta room on the speedo... ???

[SLK]

Originally Posted by Intrepid

But r u serious bout running outta room on the speedo... ???

Yup, I can confirm that... I own one!

[wolfinstein]

Originally Posted by Mp421b

Is it true, When i resetted the ECU in the Optra nothing like that happened. Does that mean the ECU did not reset??

I think you need to disconnect both the terminals for 10 min's and then reconnect them.

[Shan2nu]

I am saying that if the observed speedo readings varied from, say, 120-150 kmph on the level sections of the Expressway and if there isn't too much error in the speedo readings, your avg. should fall somewhere in between.

Yes it should, but how do you conclude as to which fig was your actual top speed? How can you be sure that the ave speed is a result of 120-150 and not 110-140 (just incase your average turns out to be 130kmph)?

It's just too complicated a method. If you want to know your average speed use "distance travelled / time taken".

Another common mistake people do while calculating ave speed is using the wrong units after the decimal.

EG : If i cover 400kms in 5 hrs 45 mins i can't calculate 400 / 5.45 = 73.39kmph, bcoz 45 mins is 75% of 1 hr. So, it makes sense to use 400 / 5.75 = 69.56kmph in this case.

Shan2nu

[rks]

Originally Posted by Shan2nu

Yes it should, but how do you conclude as to which fig was your actual top speed? How can you be sure that the ave speed is a result of 120-150 and not 110-140 (just incase your average turns out to be 130kmph)?

It's just too complicated a method. If you want to know your average speed use "distance travelled / time taken".

Actually that is what I am doing here for the straight section of the Expressway. I am estimating the total distance travelled as 80 kms, I am estimaitng the total time taken for traversing this distance as 36 mins. So the true avg. speed works out as 133.33 kmph.

Next I observe that the lowest speed that I run at in the straight sections is maybe 120 kmph (speedo). And the top speed that I reach is 150 kmph (speedo). There is a theorem of elementary mathematics (called mean-value theorem) which asserts that the average speed in a time interval should be in between the minimum and maximum speeds attained. So if my speedo readings are indeed close to the true values, my true avg. speed should be somewhere in between 120-150 kmph. This does check. Of course this doesn't prove that the true top speed was 150 kmph -- as you point out, it could have been 140 as well. But if I had found my true avg. speed as 110 kmph in the previous paragraph, I can guess that my speedo is definitely having huge errors. So this is at best a crude estimate, nothing more.

You can guess that on the straights the speed will not deviate much from the average, so if the true avg. was 130 kmph, likely that the true top speed was within about 15-20 kmph, i.e., maybe 145-150 kmph. But this is only an educated guess given the nature of the Expressway. On the other hand, to maintain an average of 100 kmph on Pune bypass road (NH4) you probably would need to do a top speed of 180+ kmph -- because unlike the Expressway there are many sections of this road where you would be slowed down by traffic to 60 kmph or less for significant periods of time.

[humyum]

Althought i am not boasting.I did a mahabaleshwar-ghatkopar run that is like 225 km in 3 hours and 10 min taking the normal road(the goa highway).It was some 4 years and half years back when i was 16 and was driving with 2 adults on board.My 800 had the company fixed thin cross ply tyres that time which enabaled it to reach a top wack of 140km on the odo many times on the trip and was doin more than 120 most of the time.Although thinkin about that day sends shivers down as i was overtaking like a a J**K at breakneck speeds.I would never ever even think about doing something like this now.

[SLK]

Originally Posted by rks

But if I had found my true avg. speed as 110 kmph in the previous paragraph, I can guess that my speedo is definitely having huge errors. So this is at best a crude estimate, nothing more.

Well, if your speedo fails this test!!... you don't need to point out that your car has a speedo!

Speedo errors are normally 3-4km/h till 130 or so... then it increases tremendously. (again depends on car)... basically as per my understanding ... the speedo would have huge error by its end...

e.g. how does zen do 160 in 5th when its measured top speed in 4th is 154 something. And an alto only does a bare 160 in 4th .. and nothing close in 5th.. thats b'coz its speedo doesn't end at 160.... and you don't have so much error at 160 itself (b'coz its not the end).