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Increase MPG with ScanGauge II

9K views 14 replies 11 participants last post by  racerraj 
#1 ·
The ScanGauge II is a plug and play monitor for OBDII equipped vehicles. I've been using one on my '04 Mach 1 and '05 Powerstroke for years. It can display a variety of engine/vehicle parameters via the ECU. You can use it to show real time instant MPG and with a few programming strokes, average tank mileage.

Instant and tank MPG display is the easiest way to improve mileage on vehicles without factory displays. Since you calibrate the ScanGauge II, it has proved more accurate than the factory MPG readouts on more modern cars I've driven.

Keeping an eye on instant MPG and tank average MPG allows you to drive much more economically when you want to. You learn that the road you thought was flat is actually a grade, that you don't have to be on the bumper of a semi to pick up a draft, which gear/speed combination is best for mileage, etc. Since there are no mechanical changes, your car retains all of its performance.
 
#2 · (Edited)
x2! The start of improving just about anything is accurate data -- having that real time/average mpg number in front of you allows you to alter the biggest single variable in fuel efficiency - you can tighten the nut behind the wheel.

It's funny - with a real time read out of tire pressures (all 4 simultaneously) I find myself watching what happens to the two that are on the sunny side of the car, or the two on the outside of a long sweeper taken aggressively. You can see the psig creep up a bit. And you realize that there's no such things as "32 psig in the tires" -- they're all changing all the time.
 
#3 ·
Do you have any measurements you made before and after you installed the unit?
 
#5 ·
The ScanGuage II won't improve MPG. That's up to you. I never ran moving averages or kept a log, but I did experiment.

I live in the middle of nowhere with long two lane highways with little traffic.
Watching the SGII, I was able to pull 24.7 MPG from my F250 Powerstroke 4X4 at a weight of 7,120 lbs. at a steady 48 MPH over 50 miles. 48MPH turned out to the most economical speed because of drag and being able to keep the auto in high gear.

There's a stretch of 80MPH on I 15 in Utah. I found out you don't have to be NASCAR close to pull a draft. I was towing a 3,000 lbs. box cargo trailer with the F250 and I tucked behind a semi cruising at 80. When I got within 100 feet, my MPG jumped from 15 to 20. I stayed behind him at 80 MPH for about 30 miles. Without the SGII I would have guessed that I would have to be kissing his bumper for that kind of improvement.

On my Mach 1, I can get the EPA rated 17MPG city by watching the SGII. You learn things like 30 MPH in 3rd is more economical than 30 MPG in 4th. I also learned that a steady 70MPH on cruise control nets me 27.5 MPG and dropping down to 65 MPH gets 29.2 MPG. 57MPH gets me over 31 MPG.

Watching the SGII will tell you the best gear for any given speed and grade and give you a lesson in what coefficient of drag is all about and the real world effects of what happens when it squares with a doubling of speed.

On the Mach, I use the SGII to monitor water temp in actual degrees F, because the factory gauge is basically an idiot light. I also scroll through other info like intake temp. It's neat to see the intake temperatures go up when the car is idling and drop with moving.
 
#6 ·
Have thought about ordering one of these for my saturn DD for a while. Does it just plug into the obdII port?
 
#8 ·
TPS is what I watch when chasing MPG. You realize that 27 on the TPS gets 5 MPG better while accelerating from a stop than 31 does but you don't even notice it the acceleration difference.
 
#9 ·
What's the big differences between the ScanGaugeII and the ScanGauge E? The E is $60 less and was wondering if i could still see water and intake temps with it. Or is the II just a better buy overall?
 
#12 ·
I was curious to see how accurate reading MPG through OBDII was. Wasn't sure if there were other variables that could mess up the reading. I run an AeroForce gauges which also plugs straight into OBDII but when im cruising on the highway the thing gets into the low 30's for MPG. Either this thing is a little off or Ive managed to build a 630hp streetcar that gets 30+MPG highway. Its a 6 speed turbo car and cruising at 80mph puts me at almost exactly 2k. But 30MPG?!
 
#15 ·
I use an ELM327 BlueTooth/OBDii adapter with Torque Pro on my Andriod phone. It is basically the same thing, but I have less than $20 in it. On my 06 Mustang GT 5 speed manual, I average just over 27mpg per tank. I tweaked my habits much like mentioned above. I also coast down hills. I have found following a line of traffic in the left lane can be as good or better as going speed limit in the right lane, long as they aren't going more than about 5 to 7 mpg faster. I don't have to tuck in too close either. Mostly highway and not much traffic in the city. 75 miles a day. The car is rated for 23mpg.
 
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