RichieRocket
New member
Yeah, I'm baffled by the DIC average MPG...very inconsistent
I'm curious to see what other people are getting? DIC vs. Calc
Does turbo require premium gas?
- Thread starter tubasonic
- Start date
Yeah, I'm baffled by the DIC average MPG...very inconsistent
I'm curious to see what other people are getting? DIC vs. Calc
RichieRocket
New member
Turns out I ran 4 full tanks of 87 Octane. No identical test cycles, but at bone stock calibration and only 4000 miles I got 37.2 MPG on 87 Octane. I have yet to eclipse that
I plan on doing a couple long roadtrips this summer also, hoping to break the 40 mark. I was disappointed back in Dec on my FL roadtrip. On the way back I tried to average 70 mph, slowing slightly on uphills, I got 38mpg.
A summer roadtrip for the same drive should get a few more mpg...we'll see.
Turns out I ran 4 full tanks of 87 Octane. No identical test cycles, but at bone stock calibration and only 4000 miles I got 37.2 MPG on 87 Octane. I have yet to eclipse that
37.2 MPG is that DCI of pen and paper????
Yeah, I'm baffled by the DIC average MPG...very inconsistent
I'm curious to see what other people are getting? DIC vs. Calc
Mine is crazy wrong alos.... also i noticed if you get good gas milage (taking it easy) then not so good (more aggressive) the DCI will give more weight the high MPG so it will reaad way high.
Gimpster
New member
That's exactly what I've seen too! Like say I've been in city conditions where it estimates 43-44, and then I rod on it excessivly. It barely moves and then I'll get a 31-32MPG hand calculated tank while its still up in the low 40's or maybe 38/39.
I've not been tracking my DIC offset, but I will from here on out.
I've not been tracking my DIC offset, but I will from here on out.
furious_pete
New member
I live around Denver (the mile high city!) where most gas stations dispense 85, 87, and 91 octane fuel. I know the Sonic owners manual specifies that I run 87, but can I get by on 85 with no problems because of the lower air pressure / higher altitude with the turbo? There is no concession in the manual for higher altitude, but the general consensus from the two local dealers I spoke to seems to be yes, that 85 = 87 at altitude. To be clear, that seems to be why we have lower octane fuel here, because most engines handle the lower octane fine with the elevation change. The turbo concerns me though. On the last car I had, a 2.0L turboed Saab, the Saab dealer told me not to put anything lower than the recommended 87 despite the high altitude.
LS1notFOUND
New member
if you reset with each fuel fill its not to bad accuracy wise.
Gimpster
New member
Just not true in my case... I always reset it. Looks like its about to be off 6-7% judging by how much fuel i have left vs. trip. By far the most optimistic fuel mpg estimator I've ever owned in a car
I reset every tank also. last time it was mixed driving .... city with four in the car (whick hurts your MPG) and just a little highway DCI read 37.x and pen and paper was 31.... grrrr
RichieRocket
New member
LS1notFOUND, I posted a list of my last 6 fill-ups on posting #78 of this thread, I reset the Avg MPG at fill-up (except the one tank marked with ' * ')
The DIC was off by 1 mpg (3%) up to 4 mpg (12%)
I need to calibrate the mileage on my Ultragauge and see if that gives a more accurate mpg tracking.
On a trip of ~450 miles the DCI read 54 and pen and paper was 49.8 MPG that was cruise control set at 59MPH the entire trip
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SteveSonic
New member
I haven't been following this thread lately but here are my numbers:
My 1.4T 6spd LTZ HB has been running on 93 octane Shell with up to 10% ethanol (the actual content is unknown to me) the last several tanks. I just passed 3,000 miles on it. I live west of Richmond, VA and drive the car about 54 miles to/from work, with about 85% of that at about 65 mph. The land is basically flat around here, with minor rolling hills. The rest of my commute, and any other local driving, is mostly open rural/suburban roads up to 45 mph. Air temps, and humidity, were well above average lately and sometimes reached the mid-80's. The original oil fill is still in the engine, but not for much longer (Amsoil coming soon). There's about 40 psi in the original-equip 17" LTZ tires.
I've been driving for fuel economy and use an UltraGauge to guide my foot. I only use the Instantaneous Fuel Consumption and % Engine Load gauges. Shortshifting into the highest possible gear is a must for economy but only if the road grade allows for it. I get down to 1,200 to 1,400 rpm as soon as possible. I don't "lug" it below 1,200 rpm if in 5th or 6th. [The engine controller does seem to have a shut-down algorithm if the engine goes below 1,000 rpm in the lower gears.]
I'm tracking everything with Fuelly. I'm averaging just under 40 mpg combined. My DIC is consistently 7-9% optimistically high.
SteveSonic
New member
That's going to be crazy-off, then.
Has anyone put their 6MT transmission car through a measured mile and compared it to a running DIC ODO?? Could our 6MT speedometers and ODO be 8% off?!?
laborsmith
New member
I have, and the DIC seems accurate, using the freeway mileage markers as my reference. On the other hand, those several times I have hand calculated, both my calc and the DIC are within tenths.
Laborsmith
Laborsmith
SteveSonic
New member
How can these different errors between different cars be explained?
Some folks have said that they changed their driving style during a particular tankful and produced a different DIC error. Was'up with this thing?laborsmith
New member
Good question. As for my driving style, I admit, and anyone who knows me will agree, I am erratic at best. Sometimes I feel compelled to get to the next light as quickly as possible and sometimes I have no trouble getting to it at a measured speed.
Laborsmith
Laborsmith
RichieRocket
New member
Hey SteveSonic, last weekend I finally got around to calibrating the mileage on my UG. I stopped at a highway mile marker, reset the mileage and then drove 13 miles, stopped at mile marker, calibrated the UG.
I was also watching the tripmeter on the dash. The tripmeter was within 0.1 miles. So assuming the mile markers are positioned properly. The Sonic's odometer/tripmeter should be something less than: 0.1/13 = 0.8% error, can't say anything better than that because 0.1 mile is the smallest increment...
If someone on a longer trip checks it against mile markers or GPS, I'd bet the accuracy is better than that. But as the tires wear out, the error will continue to increase up to ~2%
SteveSonic
New member
Thanks for the info, RichieR.
The variations between DIC-reported and actual rates currently can't be explained unless the variations are between models, i.e., LT's with 1.4T 6MT and LTZ 1.4T 6MT but a detailed analysis hasn't been done. The only variable btw those two models is the tires AFAIK.
The variations between DIC-reported and actual rates currently can't be explained unless the variations are between models, i.e., LT's with 1.4T 6MT and LTZ 1.4T 6MT but a detailed analysis hasn't been done. The only variable btw those two models is the tires AFAIK.
SteveSonic
New member
Quoting myself ... this discussion belongs in the Real World MPG thread, not this one, because the gas octane isn't a variable in the DIC output AFAIK.