jdphillips73

i'd compare your speedo and mileage against a gps unit...

hawkeye18

+1. GPS never lies. Borrow somebody's for a half hour if you don't have one.

gman73

Also on getting the correct speed for tire height, look at manufacture Revs Per. Mile then multiply by 1.03. What was your RPMSs at 70? With your tire height, your RPMs should have been just about 2450 to 2475.

2011CS

I think there is even an I-phone app for this

bilbob2

At 70 I was at around 2400 to 2450.
As long as my RPM and speed match what they are supposed to does that mean everything is both installed correctly AND tuned correctly ?

bilbob2

Never used the GPS before.

How would I do this to compare? What exactly would I do?
I know a couple of people with Iphones.

bilbob2

Oh and I think my RPMs at 70 may have been closer to 2400 than 2450.
It could have been the way I was seated though and the angle I was looking at the RPMs.

bilbob2

Man not being able to edit posts sucks@
I wonder why I can't...

Anyways... can someone tell me the name of the IPHONE app for doing this?
Will it do it by itself or am I doing the math here?

chrisheltra

This is why you always ask for your old parts back.

bigstick

I would think that going from a 3.55 to a 4.10 you ought to easily feel the difference in the seat of your pants.