larger tires on my 2004 silverado

Old 05-17-07, 10:41 AM
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Unhappy larger tires on my 2004 silverado

I have stock 16" rims and tires. Want to know if i buy 17 or 18" rims and tires will this
affect my speedometer reading. Can't find a lot of hot rims in 16" for o4 chev.
Old 05-17-07, 10:46 AM
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It's the diameter of the tire that matters, not the wheel.
Old 05-17-07, 10:52 AM
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There are a few web sites that will help you caculate speed differences with tire size changes - only I don't where they are

What I've always done is read the odometer along with mile markers on the interstate - low tech way of getting you close. You can also buy speedometer adapters to speed up or slow down your speedo as needed.
Old 05-17-07, 12:10 PM
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IT's the VSSB ( aka the DRAC, I think?)

It's a small box under or near the ECM. It's the one that adjusts the radio volume - it also affects the speedometer readings. It's possible to adjust the jumpers to allow for different tire sizes. A few have DIP switches, most have soldered jumpers.

Internet search on one of the above can yield some idea of what's involved.
Old 05-17-07, 03:22 PM
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here is a site

Google this site good info there.
Old 05-18-07, 03:22 PM
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Yes, it will alter your speed.

Look up that miate site like michael said.

You have also considered whether or not those tires will fit on your vehicle without rubbing?
Old 05-19-07, 09:47 AM
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Its not just the tires to consider fitting properly, but the off-set of rims.
Too large or small of an off-set will cause rubbing of the rubber to the wheel well..and or not clearing your calipers.
What model Chevy?

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