Firebird- Speedometer Broken....effect on odometer


I have been on a crusade to find a firebird to satisfy my mid-life crisis…in any case, I stumbled across a 95 firebird that meets my fancy;however, it turns out that the speedometer is broken. When you go 30 miles an hour, it shows 35…when you are really going 80 miles/hour, it shows 90-95. So, the topic of debate is…how does this affect the mileage that the odometer shows? Of course, it is a pain on the road because you have to always question how fast you really are going, but the topic at my office now if how is this linked to miles? I’m assuming that speedometer and odomoter are connected and so if the speedometer is suffering from the conditions mentioned above, the car would be showing more miles than it really has? Also, what are the typical reasons that a speedometer is broken? So far, I found that if the gears were changed/etc and not recalibrated and/or size of tires??? Thanks in advance,


It depends what’s wrong with the speedometer, if the gears (or tire size) were changed with out re-calibrating it, the odometer will also be reading too high. It’s also possible that the speedometer itself is off and the odometer is accurate. If you really want to find out, compare the odometer to some highway mile markers.


Craig has it right. Why guess? Test the odometer independently.


On many cars the speedo and the odo get their readings from the same source- - i.e. if one is inaccurate, the other one is too. If that’s the case, you’re in luck, because the car’s reading higher speeds than actual, which means it’s showing higher mileage than actual.