Scangauge II Fuel Economy Challenge
 

I am trying to prove to myself a ScanGaugeII is worth buying.

To have a Scangauge II pay for itself in four years I'd need to attain a year long average of 43 mpg (assuming average fuel price remained the same). Does this seem reasonable to any of you? It's an experienced based question, unfortunately. I did own one for about two weeks and learned to drive with it on the roads that comprise 90% (or more) of my driving, but I'm sure I'd be more consistent with it in place. My estimated yearly rate will be around 39.9 mpg, so that's a 7.8% increase needed for payback.

Fuel prices could go higher, but this last year did include some very higher prices as well, with an average fuel price of $2.53.

So my questions are these:

1) How likely is it that I'm going to be able to suck another 7.8% improvement above my already pretty tuned driving habits? (I'm getting 37.5% over EPA with 45 psi tires and driving habits alone at the moment).
2) What is a good working estimate for average fuel prices in the next four years - likely lower bound and upper bound suggestions welcome


I guess there is another way of approaching this. What is the chance that I'd get one and sell it off on ebay and break even. Since they seem to retain their value quite well, it wouldn't have to save me much to satisfy this failure case scenario.

There's another possibility you haven't considered... Buy the Scangauge, use it for a month or 2 to tune your technique, then package it back in the box and sell it as nearly new... Several members here have done that. Now can you save enough to justify $25? Plus, you can always decide to keep it if you do decide that it gives you better information than the gauges. Personally I like to monitor the instant MPG and average MPG on mine... Most helpful to me.

remember also that you can take the scangauge with you from car to car.

another aspect of the scangauge's value is the code reading. you have to drive quite a distance to "town" and if you needed to have a code read, you would have to go to advance or autozone which is unneeded expense in gas and you get the piece of mind of knowing what the code is earlier. most don't think about that unless their car is older.

I think that gas prices won't see a lot lower than they are. we have seen a spike but even at it's low point, we barely saw under $2/gallon.

you are also correct about the resale and that won't change. as long as it still functions properly, they usually bring a good $130 or so on ebay so you just have to get $40 worth of value out of it.

I hope to keep mine for quite some time after my car is gone. it is obd2 compatible. so it would work in pretty much any car (at least that I would get).

I already did that. Only took two weeks to learn what I could. That's why I'm not positive I can justify owning one full time. My WAI requires me measuring IAT, and I was thinking that rather than buying a thermometer I don't really need, maybe I should reconsider the ScanGauge II as I never did run the numbers on keeping it (unfortunate oversight). I think the failure scenario clinches it: if it can't pay for itself I sell it off again. I never thought too much about code reading, only ever having had a code read once in all the time I've been driving. But it is still $40 a whack, so even once would tilt things considerably.

JC Whitney has a 10% off promotion today with free shipping for things over $99, so I got one for $144. It'd be hard for me to lose selling it back off again if it doesn't pay. Wish I'd run the math previously, but what can you do? I think it's safe to assume that gas prices will at least stay at the current level, which is pretty much what it averaged over my year of keeping records. At that level it's a close call for the SG2 to cut it, but if prices rise I'm probably all set. I did have one tank at 46 mpg using it, but one isn't statistically significant. I have been assuming some other option will come along to replace the SG2 in the future, hence my four year repayment time frame.

I don't think it can pay $160 for itself for you. You put enough thought, effort, research, and practice into saving gas that you're not going to be surprised by anything you learn from it.

• If you need a code reader, they can be had for $40 at Harbor Freight; I have one from there and it works great.
• With the way you like to tinker you could even have a realtime FE gauge using a cheap DIY project for far less.
• Your car has a long warranty and you seem to be very careful about not breaking it, so seeing extra gauge data isn't going to mean much for avoiding breaking stuff.
• The only extra gauge it could probably help with would be IAT for a WAI, but an $8 remote digital thermometer will do that job.
• If you wanted to see DFCO or air/fuel ratio, there are even cheap ways to see those, and even relative fuel rate.

It's a great unit. It's a wonderful luxury for anyone interested in saving gas or otherwise interested in technical stuff about modern cars. I recommend that you get one, you probably already know how you'd enjoy it from your past experience with it. However, it will not pay for itself.

I couldn't mathematically justify spending money on one either, but I was able to get it as a Christmas gift. :)

Well if not, back on Ebay it goes! :)

That's a perfect gift: something you wanted but weren't willing to buy for yourself.

there is also the gadget factor of it too.

you're an engineer. gadgets are cool. also the fact that data overload doesn't seem to affect the engineering types too bad.

I actually considered getting a second one and daisy chaining them together so that I could monitor 8 parameters instead of 4. there again, the cost keeps me from doing that.

dang all this cost justification

I am slightly concerned that I won't be able to monitor that and also listen to podcasts. The ScanGauge won't win that fight! ;)

if your scangauge is audible, then something is seriously wrong with it. lol

a lot of guys with engineering backgrounds that tinker with cars have cars that look like space ships inside. I remeber a buddy telling me about a ford festiva that one of his friends had. put a v6 turbo in it. said the thing would glow at night from all the gauges. it would also smoke a set of tires off in a matter of minutes. he had very crazy friends.

I had a friend with a DeLorean that had plans for crazy amounts of gauges. He was going to install a daylight visible LCD screen hooked to a mac mini, then do all sorts of weird stuff from that. Already had two monitors for rear view cameras (rear visibility sucks in that thing - along with everything else IMO). The best part was that he worked from home (programmer), so didn't drive that much.

I have a friend and an uncle who've expressed interest in a car computer so I'm going to loan the SG2 to them for a few weeks so they can tune their driving. I have a kill-a-watt that has similarly made the rounds.

I've actually been trying to figure out a useful audio interface for instantaneous mpg. So far, no luck: they'd all be annoying.

I've mentioned many times over, if you're looking to monitor intake air temps, buy a cheap wireless outdoor thermometer and drop the transmitter in your airbox... I do like the Scangauge though, and I'm glad I bought mine.

-Jay

Yes, it's a really good idea, and I was going to follow your suggestion, but the process of working out cost vs benefit got me considering all the options, including the SG. If I actually had use for a wireless thermometer it might've broken the other way. As BEEF correctly deduced, however, I was basically looking for an excuse to own a car computer. :)

The excuse is that it's a great tool...not that it will pay for itself.

A 6 DOF CNC milling machine is a great tool too... :)


Took me a minute to find this...

https://www.fuelly.com/attachments/fo...0bee9d7a45.jpg

My two cents...

The scangauge ii is a great tool for improving your driving habits. It is also an invaluable tool to monitor your car's running parameters and track down problem codes.

I also just enjoy having it.

Plus, you are talking about $160 over 4 years. That is a REALLY small pittance in the grand scheme of things. You will spend about $2000 over the same time period just on internet alone... assuming you pay for your connection.

So... get it if you WANT it.

I spend $10 a month on internet....GO DSL LITE!!!!

seriously though, I know what you mean. it is a fun gadget, it may pay for itself, it may not.

I put $3k in my truck to make it go faster and in the end sold it for less than blue book (during the $4/gal days). I still enjoyed the truck and don't regret a penny I put into it.

the same can be said for my car but my investment in it so far (gassavings wise) is under the $200 mark and that is including the scangauge purchase.

a couple of interesting toys I'd like to have:

welder
port-a-band (prtable band saw)
pressure washer (stop borrowing mom and dad's)
beater pickup truck
better video camera

I can't justify any of those either.

You're quite right: even if it doesn't pay it's way, it should be close enough that I shouldn't sweat the difference. I am afflicted with stereotypical Yankee cheapness! Always have been from a young age. My brother's the exact opposite, so I'm thinking it must be somewhat genetic.

Around here it's cable, dial up, or satellite. Many parts of my town have no cable at all, so I'm actually lucky. $60 / month, though, for spotty service. I keep having to explain to the cable guys when they call that a package deal with TV is not actually cheaper if you don't value the TV part! Tolled local phone service was so pricey here that not needing it (skype) cuts the overall cost quite a bit.

I justified getting a wire feed welder by making a rip fence for my table saw (one it came with was useless and getting worse). The ones from Grizzly were expensive and the shipping was like $50. Now I need an excuse to get the gas welding kit for it...

The way those things are declining in price, I wouldn't worry too much.

Just for the record too, I am actually American. I even moved back from Japan a couple months ago... gotta update the profile!

I forgot all Americans are called Yankees in a lot of places. I meant New England Yankee. We hardly have a nationwide reputation for thrift! Even the NE one is pretty damaged.

Where in Japan were you?

OK lets put it this way - I own TWO scangauges the original I and the II that I just paid to update - was it worth the update $25 HECK YEAH! Do I look at it every day I drive the xB HECK YEAH - can I tell when a tire is low by the MPG drop HECK YEAH. Does it feel weird driving without it HECK YEAH! Driving a friend from Vermont around one day he asked "so how much did that driving cost?" So I pulled up the current fuel cost and said $1.02 averaged 51.6mpg for 50 minutes of driving . . . pretty slick if you ask me! Now what if you drive a certain route and get great mileage and another route that is shorter but yields less mileage - you can pull up the trip cost and KNOW which way COST LESS. Did I need that $60 LED Flashlight I ordered last Wednesday Probably NOT but if I ever get stuck someplace in the dark having a flashlight that can run for 1.6 hours really bright or 80 hours dim and BLINK "S O S" automatically will sure be pretty handy.

how about you make it 5 years?

Chances are I'll have moved to a more civilized by then area and my driving will drop to next to nothing. Actually, four years is pushing it.