1. Home
  2. Volkswagen, everything else
  3. RPM -> MPH Formula

RPM -> MPH Formula

I lost the Speedo and Odo on my car (still diagnosing). Is there a website that has all these formulas 1991 Jetta GL Bone stock (i.e. No transmission swaps and normal sized tires). Or if the formulas are too difficult could someone write down the RPM for these speed (and associated gear) 20 35 60

And, for my knowledge what is 4.5K in 5th gear? That was after Christmas I-80 near Chicago traffic. It felt a bit faster than normal, I was just wondering how fast.

And for the future, what will make both die? I'm hoping it's not the gearing, I have to tear apart the dash and make sure that it's connected. If it is the transmission gear thinngy, how much and where?

Reply to
Matt Anderson
Loading thread data ...

Does the cable turn when you go down the road?

If no, then you either have a bad cable or a bad speedo gear.

If they go roundy-roundy okay then you have a bum gear in the console (which I haven't heard of).

Tim wohlford '89 golf

Reply to
Tim Wohlford

Here's what you need.

formatting link
. With both theodometer and speedo broke at the same time I'm betting that it's the speedocable. I'm not sure if your car has two but if it does hopefully it's thelower one its a lot easier to replace. HTH Steve

Reply to
sehaare

As other have replied, traditionally, there is a cable from the transmission to the speedo that twists to transmit the info needed for the speedo to spin at the proper RPMs and drive the needle appropriately. If that breaks, both speedo and odo are kaput.

However, some new vehicles don't have a cable any more. The pulses from the vehicle speed sensor in the trans (that the fuel injection/ emissions systems use) is the signal used for the speedo/odo. If it comes unplugged, you lose the speed/distance inndications. If the sensor goes bad, you usually get a "Check Engine" warning and the vehicle may run a bit less efficiently (or not at all).

Good Luck, Mike

Matt Anders> I lost the Speedo and Odo on my car (still diagnosing). Is there a

_______________________________________________________________________________ Posted Via Uncensored-News.Com - Accounts Starting At $6.95 -

formatting link
The Worlds Uncensored News Source

Reply to
Mike Spera

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.