800+ Mile ECO MT Tank Range

I'm somewhat fortunate that my daily commute is moderate speeds. It's half a mile to the main street which is 45 MPH for another half mile. Then the speed boosts to 50 for a ways. Then I hit a 55 zone for a few miles followed by 18 miles of 65 MPH freeway followed by about a mile and a half at 45 or slower. In the mornings I drive 60 on the freeway, which still means I'm passing on occasion. I tried 55 one morning and was a rolling road hazard - I'm not doing that again. Mornings are a net 200 ft downhill and I have actually seen 59 MPG by the time I get to work. Coming home I reverse this and have to deal with traffic. I-25 through the Denver Tech Center is a 5+ lane highway in each direction and the right two lanes are usually moving at 55 or slower in the afternoon. I stay in the lane at 55. Then I hit C-470 and it's stop and go for 9 miles. I can manage 48-49 MPG in stop and go traffic when there are no stop lights that make you sit. Then it's back to the 55 zone followed by the 50 and then 45 zones. It is not a super hilly route but it sufficient that I have to pay attention to my gear to ensure I take advantage of DFCO. Fortunately 50 MPH is fast enough for the car to enter DFCO in 6th gear. I don't coast with the clutch in or with the engine off.

The only performance mods I've done is to set the plug gap at 0.035" and I run my tires at 45 PSI cold. Driving tricks that I use, especially since I have hills near where I need to change speed is to use gravity to accelerate down hills or slow down going up hill. This way I avoid the throttle and I can also avoid throwing away momentum by braking. End of shift targets on level ground is 1400 RPM or lower while accelerating and 1600 or higher when decelerating. This keeps the car out of boost during acceleration and immediately reengages DFCO during deceleration.

Today I left my house at 52.5 MPG and when I got to the gas station a mile from home this afternoon I was at 52.6 MPG. The final mile would have brought it back down to 52.5. I wouldn't even be attempting this if I hadn't just spent the last full month running at 50+ MPG as measured at the gas pump.

Here's the elevation profile. The morning drive is left to right and the afternoon is right to left.

No fuel tank mod. The complete mod list for my car is:

Spark Plugs from 0.023/0.025" to 0.035"
OEM Goodyear FuelMax Assurance running at 45PSI cold
Bluetooth PDIM for streaming music
VG SharkFin
"Chrome" covers for my fog lights
GM Spare Tire stack, which I left in even though I have the original trunk floor in my garage.
[URL="http://www.cruzetalk.com/forum/11-appearance-body/6499-korean-gm-sunglass-holder-install-north-american-cruze.html]Korean Cruze Sunglasses Holder[/URL]

Even with the fuel tank mod this would be dicey because it will require I maintain 51+ MPG (52+ on the DIC) for the entire tank and I will be driving the car down into the "Low Fuel" warning, at which point the car won't give me a range to empty estimate. I'll have to watch when the low fuel warning light comes on and also when the range estimate goes away to know how much further I can really drive. Prior to my learning to drive 50+ MPG these numbers were 60 and 40 miles. However, at 50+ MPG the light comes on at 67 miles and I haven't seen the text warning.

I did park my car facing downhill on my driveway last night to help keep the fill pipe and evap system at the highest points in the car (don't know if it helped the car but it helped me). I won't need to do that today as I will have burned slightly more than a gallon of gas when I get home and there won't be any gas in the fill pipe.

When I got to work this morning the car read 57 MPG and the range had increased from 647 to 673 miles. Estimated total range is currently at 704 miles but until the fuel level in the tank starts to drop I won't have an accurate distance to empty estimate. The needle hasn't moved.