OBD1 version of ScanGauge?
 

So, I checked out the ScanGauge website, and I see that it is only useful on OBD2 vehicles. Being as my GTi is an OBD1 beast, ScanGauge is useless to me.
Is there something out there that is as useful for us OBD1 types?

OBD1 isn't as much of a standard as OBD2. Even if there was a unit like scangauge it would need to be different for almost every make, something that isn't very cost effective, especially with OBD1 cars making their way to the junkyard more often than not anymore.

In short, no, there isn't.

I think there are several DIY versions if you are willing to do the work.

I have never used them as all my vehicles are obd2 but there are a few people that have done it floating around here.

Bummer. I've got too many other projects going on to take on building something like this.
lol

You too huh?

They keep piling up! I almost can't keep up with the projects anymore. I've actually got some that I've got all the parts for, just haven't started them yet.

There's a link in my sig for a DIY fuel rate meter. It's no replacement for a ScanGauge but can give you useful information. However, the thread has links to other projects that will provide better information (for more effort and cost).

However, you may be able to use Ross-Tech Vag-Com for lots of data collection, if not MPG.
https://ross-tech.com/vag-com/index.html
I'm not sure if they support pre-OBDII VWs, but I think they do.

I looked at that, and the VAG-COM is mentioned A LOT on a couple of the VW boards I'm on. Where I couldn't tell if you can get an MPG indication, I was able to determine that it will indeed work on my car.
I'll have to wait for a little while, though... the full license and the cable will set me back $250. They do have a shareware version of the program and there's probably something out there on building a cable.

There's a kit you can buy to make a device called a MPGuino that will work on any fuel injected car with a speed sensor. I think the kit is about $40., but you have to assemble it yourself, unless you can find someone that is assembling them and selling them.

You cannot build your own Vag-Com cable. At least, there was no documentation on doing it or even on anyone's attempt a year ago when I wanted to. It's not just a cable that crosses a few wires and runs them through a resistor or two, it's a complex electronic device. The license for the software is the cable itself acting as a dongle, so if you make your own cable you won't be licensed for the software; IIRC, without a license it won't connect to the car.

There are all kinds of things you can customize on the MKV with a Vag-Com. I doubt your older car offers the same variety, but it probably still has some good stuff.

The software won't give you MPG, but it can give you logs in CSV format which you may be able to turn into MPG, either after the fact or by tailing the log* and feeding it live through your own software. With my car it offered pretty much all the standard OBDII data and I could probably have logged O2, MPH, and MAF to crunch into MPG; I don't know what data you'll be able to get.

*: I'm not sure I remember correctly if it logs by default in CSV or if I exported its proprietary logs to CSV.

Anyway, the data and customization it offered for the MKV are great and it's at least worth buying and re-selling later if you don't want to permanently part with the money. You can easily sell it for nearly as much as it sells new, and the end result is like renting it. If you buy it used you'll be able to sell it for the same price and you've only paid shipping in the end.

I'll have to look into this, and maybe build one when I get the time. I just took a "promotion" at work, so my "free time" just got shortened a little.

SNAPS! Oh well.

All the V-Dubbers on the VW sites I'm on, be they in MkIII's, MkIV's, or MkV's swear by the VAG-COM system. It must do something amazing, even for MkIII's. lol

I've no real need to see what my true real time MPGs are. The trip computer, which I've found is controlled by my fried Cruise Control Module, gives me a rough enough figure that I can use it to keep my wastful driving in check. I'm not beyond figuring it out myself every so often using Excel.

Good point. I think I'll look for a used one when I have the funds. Thanks for that advice!