Re: RPM at 65, 70, 75 MPH?
[quote author=ewmatter link=topic=51301.msg818180#msg818180 date=1152722053]
it looks like 909 posted speeds for the speed3....155mph is the top speed for the speed3, not your everyday 3.
That chart is not a "Mazda 3 speed chart" It's a mathematical chart based on gear ratios and tire size. It just happens the input I used was the specs of the 3. We use charts like this when determining gearing changes, tire size changes, etc... The original post was asking if there was a problem with her 3 beacause it rev'd so high at highway speed. If your clutch is slipping it can be a problem but how do you know for sure? Easy, look at the chart. If your engine RPM doesn't match the mathematical answer then there is slippage somewhere. The chart does not imply the car goes 800 MPH, or that the engine revs to 8k freely. Please don't interpret it as such.
When you're in 1st gear and floor it, the rev limiter will kick in eventually preventing you from grenading the engine. This is an electrical kill to the spark. When you're in 4th and hit 118MPH and you're not at the ignition limiter, the top speed limiter kicks in and it kills fuel, these are 2 different limits, remember rev=spark and speed=fuel.