Ok is there anything besides having a different gear ratio in the rear that will cause a tach reading 500RPMs fast? shouldnt be the tach cause its brand new and i have it properly installed. i ask cause after using the tech equations on the main site it says that if im going 70mph@2600rpm i should have like 4.10s or 4.11s i would not believe this other than the numbers match up exactly and i have an acurate speedo cause my speedo said the same thing the cop did on my last ticket.

this has me wondering enough that im gonna change the diff fluid and count the teeth on the gears in there. 99% chance says that my new tach is crap and i have some thing more wrong with the car causeing my horrible gas mileage. its due for a diff fluid change.

EDIT: i just noticed a MASSIVE hole in my prior statement. Is there a Speedo Drive/Driven gear combo that will keep the speedo acurate with a 3.72 or 4.10?

 

The guages in our cars are notoriously inaccurate, so perhaps the new tach is reading correctly.

JamesC

 

The only thing I can think of is when you change your rear gears, you also have to change the speedo .. not sure what its called, but its like a gearset for you speedometer.

 

Bah im curious enough about this that im gonna go change my dif fluid.

Hah i just thought of a crazy idea what if my speedo IS off but just by the correct ammount for different gears? LOL that would be the craziest crap in earth.