I just went from 205/75/15's to 235/75/15's.......I think it will help the mileage a bit. The tires are new and FREE! How do I correct my speedo? I've heard of a ?module? somewhere in line with the speed sensor and head. That you could use one from a 1/2 ton truck and be fine.......Anyone heard of this?
there is a ring in the tranny you have to change from what I have been told, and that it is too much of a bother to mess with it. My tires(275/60r15) throw my speedo off but I just compensate, after all, the speedo is "for referrence only"!
what year astro do you have some (88) up are electric and older are mech from what i understand the elec are set up in the computer but i maybe wrong besides the speedometer only tells you what you want to see not what the radar tells the police for your ticket drive fast take chances either way you can get a ticket going to fast or going to slow
The electronic speed sensor equiped vehicles from GM use what is called a DRAM module to to drive the spedo for a specific gear ratio. It is located under the drivers seat in a full sized chevy . I am not sure where it is in the astro. The problem is that it is only offered by GM in axle ratio's that were oem. Your tire size change sounds like something that needs to be custom calibrated. Where and by who I can't begin to tell you ! Trust me on this ! When I wanted to put 373's in my van I asked about 20 people and got 20 wrong answers about this subject. I was even told that there were pins on the back of the spedo head ( NOT )from a very popular guy named Mich Snieder. The moral to the story is that if it doesn/t affect the spedo or more impotantly the fuel curve and trans shift points leave it alone.
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