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Old 19th July 2007, 19:20   #16
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But u r not doing too much of extra reading as per your stock and after market tire size Difference in circumference is just 0.1%, so be relaxe and enjoy driving.
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Old 19th July 2007, 19:46   #17
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i do not think you need to loose to much sleep over this. actually the upsizing that you have gone in for makes a -0.1% difference in speedo display (odo is related, obviously). But then what does that mean? It means when your car speedo shows you that you are running at 100kmph your actual speed is 100.1kmph. Nothing meaningful.

Your odo again will report the same sort of error. For 1 lakh kms of travel it will show some 100 kms less. I guess you see the point here. Its not something worth bothering about.

There is also a small matter of speedo error which is there in almost all of them from day one. Most of the speedos show optimistic speeds by a fairly bigger margin. If anything this small under-reporting may actually help you get closer to the real figure. So rejoice.
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Old 20th July 2007, 08:52   #18
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thanks. i thought it was making a big difference. i did not know it was only 0.1%.
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Old 20th July 2007, 15:08   #19
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Quote:
Originally Posted by hemanthisgreat View Post
thanks. i thought it was making a big difference. i did not know it was only 0.1%.
Here is a handy tire size calculator: Tire size calculator
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Old 20th July 2007, 17:06   #20
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but what if we want to upgrade without looking at this calculation. Is it recommended provided it does not fault with the body even on full turns. In this case how can we ensure that the speedo is corrected. Any idea.
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Old 20th July 2007, 17:48   #21
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Quote:
Originally Posted by gemithomas View Post
but what if we want to upgrade without looking at this calculation. Is it recommended provided it does not fault with the body even on full turns. In this case how can we ensure that the speedo is corrected. Any idea.
gemithomas, the question is not just that of whether the new tires foul with the wheel well. its a lot more intrinsic. you can not just upgrade to any size that you wish for. for that you need to know the rim size (diameter) and the pan width (in which the tube and the tire fits in). You also need to find out the section height of the existing tires. From this you calculate the total rolling radius (rim+tire) under the existing setup.

Once you know the rolling radius the idea is simple. Whatever setup you go for the total rolling radius needs to stay the same. So if you are upsizing (say 13" to 14") then of course the new tires that will go in will have lesser sidewalls (section height) to compensate for the bigger rim. The width of the tire is also important as depending on the pan width of the rim you got to decide this factor. Generally I think a 60% squeeze is ok. But anything more causes problem with the stability, tire life etc.

So you see, there is no running away from this maths. Thankfully for most standard tire setups readymade charts tell you the various combinations that will fit in. That is how I am sure even the great hemant got his new tires. His dealers would have suggested him the correct size. But it helps to have the understanding and the base clear.
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Old 2nd July 2008, 12:00   #22
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Default Recalibaration of odometer for M800.

Hi, I have a 14 year old Maruti 800. In those days it used to come with bias ply tyres. But nowadays every one uses radials so I changed to radials. I.e. from 3.5-12 to 145/70 R 12. From the looks, it seems the radials are slightly lesser in height. My question is do you need to recalibarate the speedometer/odometer. I am tracking the fuel consumption closely for last 6 months and it gives me more than 19.5 kmpl. I drive mostly on the highways. So I am not sure it is the real number or the calibaraton error.

Thanks.
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Old 2nd July 2008, 13:23   #23
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In my Scorpio of 2004 he stock tyres were Bridgestone duelers H/T 235x75R15.

I recently changed them after 70K kms to Bridgestone Duelers A/T 265x75R15 up size. While I know that the actual difference in speedo reading is +6 kms i.e. if the speedo is showing 100 kmph then actually it is doing 106 kmph, I would like to know the difference in the odo reading as that would help in calculating the FE.

At this moment, my FE readings are erratic although the vehicle is performing as before without any problem..
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Old 3rd July 2008, 08:55   #24
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Default Speed from gear box

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Originally Posted by nitrous View Post
I just learnt that for a lot of cars, the speedo reading is taken from the Gearbox.
Eg. Baleno!
Small diversion from topic..

Guys please explain how the speed of the car is taken from gearbox.I mean the actual setup to get speed from gearbox.

Thank You
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Old 3rd July 2008, 13:21   #25
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Open the hood of the Esteem and trace out the end of speedo cable and see where it ends in the engine bay. You'll get a fair idea.

Quote:
Originally Posted by recshenoy View Post
Small diversion from topic..

Guys please explain how the speed of the car is taken from gearbox.I mean the actual setup to get speed from gearbox.

Thank You
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Old 21st April 2011, 17:42   #26
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Default Re: Odometer recalibration

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Originally Posted by moralfibre View Post
The Palio odometer is electronic, i.e. there is a sensor at the wheel which relays information to the ECU and which in turn conveys information to the speedometer. I doubt whether any recalibration is possible.
Can some one plz point the exact location of the ODO sensor ?
which wheel has the odo sensor ,
my palio 2002 , 1.2 odo meter numbers and trip meter stopped working ,
the needle for KMS works fine .
if u can post a pic it would be a great favour .
thanks
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Old 21st April 2011, 22:39   #27
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Default Re: Odometer recalibration

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Originally Posted by octane_fx View Post
Can some one plz point the exact location of the ODO sensor ?
which wheel has the odo sensor ,
my palio 2002 , 1.2 odo meter numbers and trip meter stopped working ,
the needle for KMS works fine .
if u can post a pic it would be a great favour .
thanks
Hey octane_fx, its the speedo sensor at the wheels/gearbox.

In your case, as speed is still shown, I guess the mechanism which connects the speedo>odo>trip meter is damaged in the console, and not a sensor issue.
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