ScangaugeII Accuracy??

pamike

Active member
Joined
May 6, 2007
Location
PA
TDI
Trying to buy one
Are they more accurate than the trip computer that comes from the factory (like the one installed in my Dodge truck)? I know from hand calcs that the dodge computer is off at least 2mpg - which is 10% of 20mpg.

I am really interested in increasing my economy and looking for help. I am getting a consistent 50 mpg with my current driving habits, but sounds like I could do better with more knowledge.

Thoughts?
Mike
 

AudiLikeA4

Veteran Member
Joined
May 26, 2004
Location
Middle Tennessee
TDI
2004 VW Golf GL Anthracite Blue Manual
Every tank you recalibrate, so with more tanks it gets more accurate. It also varies with your driving habits. Fueling can change if you start driving like a race car driver compared with driving like grandma. I drive like a madman on the highway P&G'ing and get between 58-70mpg hwy according to SG. my last tank was 53.2 real mpg, SG said 55mpg, but my driving habits were different than usual...So I expected it, usually it's within .3mpg of my actual.
 

dieseldorf

Top Post Dawg
Joined
Oct 11, 2000
Location
MA
TDI
ex- 1996 wagon, ex-2000 Jetta
Pam, it takes some time to get it calibrated so it syncs up with your manual calculation. Be patient!
 

darkscout

Grammar Scout
Joined
May 28, 2006
Location
Michigan
TDI
2003 Golf
Since I got the 3.15 update I'd say it's been about dead on +-0.1 gallon at fillup. Which is pretty close estimate for MPG.
 

Thunderstruck

Veteran Member
Joined
Feb 19, 2004
Location
Chicago
TDI
2015 GTI SE 6M
How was it before, and is the updated software supposed to increase accuracy? Mine still has the original firmware, I just hate to go w/o it for 2 weeks. I'm at 3.01 right now on mine.
 

nicklockard

Torque Dorque
Joined
Aug 15, 2004
Location
Arizona
TDI
SOLD 2010 Touareg Tdi w/factory Tow PCKG
40X40 said:
Yes they are. It takes a few tanks to get them calibrated and you must fine tune them each fill up.

You can download the manual from the manufacturer website.

http://www.scangauge.com/

Bill
Mine's fine tuned enough. I don't mess with it much anymore. I just string together several partial tanks, typically about 2400 miles of driving, then tally up the gallons consumed. It hardly changes much anymore, unless I'm going from winter fuel to summer fuel.

I consider the SGII to be accurate to +/-2.0% and precise to +/-2.5% or better once dialed in.
 

FLMan

Veteran Member
Joined
Dec 29, 2000
Location
some planet
TDI
None right now
Would it be really worth it to get Scangaug if I was more concered about performance and the overall heath of my car rather then the fuel mileage? How would it bedifit me? Can it do the things the Vag-com can do?
 

heno

Veteran Member
Joined
Nov 24, 2003
Location
Proud to live in America!
TDI
Jetta TDI '03
You can keep track of your engine sensors with SG. Once you know what's normal a bad sensor (MAP, IAT, etc.) should jump out at you. You can also read and clear codes. Once SG is setup and calibrated properly it is very accurate. I don't touch mine now that it's adjusted right. The only thing that varies is total fuel use if I fillup at a different pump (to be expected) but mileage etc remains the same.
Mike
 

FLMan

Veteran Member
Joined
Dec 29, 2000
Location
some planet
TDI
None right now
heno said:
You can keep track of your engine sensors with SG. Once you know what's normal a bad sensor (MAP, IAT, etc.) should jump out at you. You can also read and clear codes. Once SG is setup and calibrated properly it is very accurate. I don't touch mine now that it's adjusted right. The only thing that varies is total fuel use if I fillup at a different pump (to be expected) but mileage etc remains the same.
Mike
Do you know if any one makes one of these with more functions, like a radar laser detector? Also, the CEL is on all the time because of an EGR delete. Is the scan gauge going to be alerting me of this all the time, or is there a way to turn this type of detection off?
 

McBrew

Top Post Dawg
Joined
Oct 30, 2002
Location
Annapolis, MD
TDI
2003 Golf GLS TDI, 5 speed, Silver/Grey
FLMan, the scangauge does not "alert" you that there is a code. You can press a button to scan for codes, then read them, then choose whether or not to clear them. So, no... it won't annoy you if you have a code.
 

FLMan

Veteran Member
Joined
Dec 29, 2000
Location
some planet
TDI
None right now
McBrew said:
FLMan, the scangauge does not "alert" you that there is a code. You can press a button to scan for codes, then read them, then choose whether or not to clear them. So, no... it won't annoy you if you have a code.
Thanks McBrew, so the whole family of 6 runs on Bio too? How much does that cost you to make per gallon? We do alot of work for restaurants with deep fryers, prolly could run my whole fleet on that stuff?
 

McBrew

Top Post Dawg
Joined
Oct 30, 2002
Location
Annapolis, MD
TDI
2003 Golf GLS TDI, 5 speed, Silver/Grey
All the TDIs are running bio (well, my mom's 2004 Jetta probably only runs on bio 1/3 of the time... she's on the road a lot). My RV (GM 6.5 TD) runs on bio. The Sprinter van runs on bio. The tractor (Ford/Perkins) runs on bio. My cousin's 300SD runs on it, too. Yep... everything except for the generator, which is our only gasser.

Due to the cost of methanol being through the roof at the moment, the bio is coming out to about $1.40/gal. In the winter, we blend up to about 30% kerosene, so that adds a lot to the cost. Still a heck of a lot lower than D2!
 

DFWDieselJet

Veteran Member
Joined
Oct 27, 2007
Location
Flower Mound TX
TDI
04 Jetta
Scangauge (once calibrated) is as accurate as you are consistent. SG reads RPM, MAP, LOAD and temps and calculates fuel consumption along with your correction factor. Unfortunately, this doesn't take into account a few factors like EGR and injection timing/quantity for emissions purposes. So if you drive consistently, it will be accurate ON AVERAGE. It may not be very accurate at any given condition, however. For example, many here believe (and I'm coming to agree) that the idle fuel consumption reported by SG is way off. I think that's a big reason why highway vs city driving produce different calibrations (my all-city is -30%, while my all-highway is -17%).
 

40X40

Experienced
Joined
Feb 12, 2006
Location
Kansas City area, MO
TDI
2013 Passat SEL Premium
DFWDieselJet said:
Scangauge (once calibrated) is as accurate as you are consistent. SG reads RPM, MAP, LOAD and temps and calculates fuel consumption along with your correction factor. Unfortunately, this doesn't take into account a few factors like EGR and injection timing/quantity for emissions purposes. So if you drive consistently, it will be accurate ON AVERAGE. It may not be very accurate at any given condition, however. For example, many here believe (and I'm coming to agree) that the idle fuel consumption reported by SG is way off. I think that's a big reason why highway vs city driving produce different calibrations (my all-city is -30%, while my all-highway is -17%).

Yep, that is why you need to tweek it a little bit each fillup. YOU(we) change, weather changes, traffic conditions change... the SGII doesn't change unless we correct it.
Just keep an eye on it....

Bill
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Is it more accurate than a tweaked MFD display using Vag-Com? With either you still have the problem of different driving styles, highway/city driving and tweaking to get it close. I don't see either being more accurate than within 1 or 2 mpg anyway unless your driving style, route, load and conditions never vary much.
 

mcroth

Veteran Member
Joined
Feb 3, 2007
Location
Grafton, OH
TDI
02 Jetta
I'm kinda confused by the mpg issue with scangauge? Shouldn't it simply be distance/fuel used? Doesn't it get fuel used by the injection quantity & rpm & distance by tire size & wheel rpm? What do driving conditions & fill-ups have to do with it? I'm guessing I'm missing something, but what?
 

DFWDieselJet

Veteran Member
Joined
Oct 27, 2007
Location
Flower Mound TX
TDI
04 Jetta
mcroth said:
I'm kinda confused by the mpg issue with scangauge? Shouldn't it simply be distance/fuel used? Doesn't it get fuel used by the injection quantity & rpm & distance by tire size & wheel rpm? What do driving conditions & fill-ups have to do with it? I'm guessing I'm missing something, but what?
That's the misconception...it doesn't "get" fuel used...it "gets" load and RPM (and a couple of other even less relevant parameters) and calculates fuel used.
 
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