Glad I searched before posting.. I was just about to post a quick review on my new ScanGaugeII..
I just bought one of these for myself last week. So far I've only been running it in the Miata (my daily-driver/commuter car), but I can't help but think that this is the coolest gadget ever!
Years back I bought a OBDII interface box so that I could link my laptop to the OBDII port and collect realtime stats and/or read/clear codes. John did the same (well, actually he just bought the IC for it and built his own from spare parts) and then wrote some software
to interface his palm pilot to it. I never had a palm pilot, so no dice for me. It was either carry the laptop in the truck, or not use the interface.
I had been kicking around the idea of building my own mini-interface to this thing using a 'single board computer' and a cheap character LCD. I'm a software engineer by trade and have some knowledge on how to do this. Unfortunately it seems I don't have the time or inclination to do this. 2-3 years later I still have the parts in a paper bag in the closet.. w/ no circuit or software designed!
This thing does almost everything I had dreamed of doing and a few things I hadn't considered. It is really awesome.
The real-time mode gives you four 'virtual gauges' where you can monitor different stats including:
- Engine RPM
- Intake temp
- Coolant temp
- Spark advance
- Instantaneous gas mileage
- ..and a few others I already forget
It also has a 'trip' computer mode.. which is really what I bought it for. This mode keeps running averages and maximums of stats like speed, coolant temp, and most importantly, mileage. It tracks stats for the 'current' run (since the engine was last started), for the day, for the previous day, and a special 'tank' mode. The tank mode gives stats for the current tank of gas. You tell it that you are onto a new tank by manually telling it that you have refilled the tank. In tank mode you also get distance, fuel used, and time on the current tank as well as distance, fuel and time left on the current tank. That makes this a really full-featured trip computer. The range on the current tank is really useful for those "can I make it to that next station" instances.
Lastly it has a code-reading mode that will read and clear DTC codes. I haven't used this feature much as I don't have any codes to read or clear.
Out of the box not all the features work perfectly. You have to dial it in for your car. It has adjustments for adjusting the size of the tank, the type of engine you have (includes 2 special diesel modes), the error in your speedometer, and a few other settings. These help adjust for non-stock items including bigger tires or folks who might have regeared. By comparing to my hand-held GPS I found that my Miata's speedo is off by just a hair.. but the number reported by the scan gauge is ***** on. The fuel usage seemed off a little on my last fillup: I pumped more than it said I had used. This is adjustable as well.. so my MPG and range numbers should be more accurate going forward.
Things missing include the ability to 'save' settings for multiple vehicles. The folks that sell this thing (Linear-Logic) will gladly sell you more interface cables. The idea is that you can permanently install the cable in the car and just move the scangauge device. Unfortunately since you tailor so many settings to the specific car that isn't really useful.
Also I would think it would be easy to implement some 'performance' features. John and I always sort of imagined a way to have the car at a standstill.. put the thing into '0-60' (or 0-100, or 1/4 mile) mode and then have it start counting time when you start to move. You'd accelerate as hard as you can and the thing would compute your cars time for that mode. If the computer knew the weight of the car (and driver) then I think it compute a rough guesstimate of the HP output at the wheels. I think this would rock. A quiet stretch of interstate in the off-hours would be all you'd need to do real A/B comparisons w/ perf mods on the cheap. Of course that wouldn't be legal! I have a sneaking suspicion that Linear-Logic will never go near this idea because of the legal/liability issues.
Also missing is any sort of upload mode/port. You can't 'download' the data to a PC or anything.. or hook a laptop into the scangauge and get realtime data through the OBDII interface either. Those aren't really show-stoppers in my eye.
From the the scangauge website:
The TRIP modes in the ScanGauge II can be used to save gas. Improved driving habits can improve fuel economy by up to 30% according to a US Government source. The ScanGauge II lets you try different driving techniques and routes and gives quick feedback on how they affect fuel use.
I believe this! 30% is probably an over-exaggeration, but I strongly believe that if you are conscious about your current mileage it will encourage you to drive less aggressively and get better mileage. That can be huge for high-mileage commuters..
Price is a bit high at $170+S/H. I got it for less direct from Linear-Logic through a group-buy through another car forum. It seems deals on this pop up every now and then. Still.. it isn't a cheap toy.