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-   -   Speedo issues (https://www.ft86club.com/forums/showthread.php?t=58115)

Venator 02-12-2014 09:17 PM

Speedo issues
 
So I was looking at some 18 x 8.5 wheels and found that it puts the speedo all out of whack:

http://www.tacomaworld.com/forum/tir...255x35xR18.png

Is there a way to compensate for this?

Burrcold 02-12-2014 09:24 PM

Don't look at your speedo?

jvincent 02-12-2014 09:30 PM

Quote:

Originally Posted by Venator (Post 1525230)
Is there a way to compensate for this?

No. Geometry is geometry.

If you car about a better match for the speedometer, go with 245/35. If you really want 255, subtract 1 when you look at your speedometer.

Of course you are assuming that the speedometer was actually 100% accurate with the stock tires.

Venator 02-12-2014 09:31 PM

Quote:

Originally Posted by Burrcold (Post 1525255)
Don't look at your speedo?

:burnrubber:

Venator 02-12-2014 09:32 PM

Quote:

Originally Posted by jvincent (Post 1525268)
No. Geometry is geometry.

If you car about a better match for the speedometer, go with 245/35. If you really want 255, subtract 1 when you look at your speedometer.

Of course you are assuming that the speedometer was actually 100% accurate with the stock tires.

Agreed, I was just curious if this was something that a tune could "sort out"

kidgogeta 02-12-2014 09:50 PM

Quote:

Originally Posted by Venator (Post 1525276)
Agreed, I was just curious if this was something that a tune could "sort out"

the tune for my dodge ram takes into account tire and wheel size and adjusts the speedometer accordingly, not sure if there is anything out for the twins:iono:

Imrac 02-12-2014 10:15 PM

While driving subtract one when going more than 30MPH (assuming it rounds)?

KONVERTER 02-12-2014 10:42 PM

get a tire size with the exact same diameter as the stock tires... But make sure they never ever ever wear, because the slightest amount of tire wear even on the stock tires is going to change the speedo readout... air pressure too for that matter... get Nitrogen quick so air pressure is constant.

h4nh 02-12-2014 11:17 PM

1 mile per hour off.. seriously?

mwjcyber 02-12-2014 11:55 PM

Quote:

Originally Posted by h4nh (Post 1525528)
1 mile per hour off.. seriously?

This^

Venator 02-13-2014 12:59 AM

Quote:

Originally Posted by KONVERTER (Post 1525441)
get a tire size with the exact same diameter as the stock tires... But make sure they never ever ever wear, because the slightest amount of tire wear even on the stock tires is going to change the speedo readout... air pressure too for that matter... get Nitrogen quick so air pressure is constant.


No need to be sarcastic, it was an honest question... Obviously tires wear and that alters the accuracy but I was curious if there was a way to minimize the margin of error.

KONVERTER 02-13-2014 02:07 AM

It is already very minsized. Plus you are putting less miles on your car, better for you when it comes to warranty.

Never heard of a dealer saying they aren't going to warrant something because mileage isn't Accurate due to tire size putting o n false mileage.

JP 02-13-2014 03:23 AM

have you checked the accuracy of your speedo on stock tyres? Mine reads high by 5% on the stock setup

JS86JS 02-14-2014 12:25 AM

Use a navagation system.
Not the cars one obviously, but one you stick to your windscreen. Or download the 'Tom Tom' app from App Store to test.
2 different brand of navs at 100km/h (cruise control on car) read 95-97 on the navs.
So I can only assume the stock car odometer is 4-5% slower than what it says for speeding issues etc.
it's reported that on average all car speedos are anywhere between 2-10% out of actual speedo readings to save you if you accidentally go 65 through a camera it's actually 60 or so (according to wheels magazine)

Or get an incredibly thin tire, same diameter as stock or become comfortable with going "60" but actually doing 61!!

The choice is yours :p


Injen Catback, Injen CAI, Borla UEL headers, ecutek tune w/ racerom, alloy pulley kit, Yokohama Neova AD08; 189hp at the wheels best dyno


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