Tire pressure?

 

Your results are about the same as mine are with 5K on tha car and 3500 of those are on gas. Your headline mentions breakin?? There hasn't been a recommended breakin for a long while. Couple that most new cars have either a semi-synthetic oil from the factory or full synthetic. The idea of a wear-in period is gone because they have cut wear to nil. Many engines have been disassembled after 150K miles on synthetic oils to find no measurable changes in clearances on rings or engine bearings. I think finding fuels without alcohol could boost your mileage by 10%++. Don't they sell tractor fuels without alcohol in Wisconsin?? It's probably 89 R+M/2 rated. Find a friendly farm who would sell some???? 40PSI in the tires??

 

For highway driving, start out electric until you hit cruise speed. Engage hold and keep at least 10 miles of charge ( generator will not run away as much with a ten mile buffer). Use L to slow at off ramps. I get 39 mpg at 74 mph. At slower speeds 40 or 41. I don't think you can expect better.
I don't think there is a break in for the engine. There is for the driver.

 

ICE MPG Increasers (for any car):
Higher tire PSI
Speeds less than 60 MPH (55 MPH better)
Cruize control
Slow, smooth starts
No rain, snow
Moderate temperatures

And yes, the Volt requires high test premium for the best MPG, (though some will disagree with the GM engine engineers and claim any old gas will do).

 

55 mph
http://www.mpgforspeed.com/

According to studies backed by the department of energy, the average car will be at its advertised MPG at 55 mph. But as the speed increases:

- 3% less efficient at 60 mph
- 8% less efficient at 65 mph
- 17% less efficient at 70 mph
- 23% less efficient at 75 mph
- 28% less efficient at 80 mph

See the graph below (from fueleconomy.gov):

 

Don't think break-in is necessary. I rarely use the engine, but have two short trips logged
1) summer night, no AC or other loads. Cruise at 105 (approx 65MPH), zero stops (except short distance in town after freeway)
26.6km, 1.33L = 5L/100km CS-only ~47MPG
2) fall night, moderate AC use for defog. Country roads with a few stops for lights, average probably 80-90 (approx 55MPH)
16.6km, 0.88L = ~5.5L/100km ~43MPG

Speed is really the key. And AC use. Heat not really an issue once you're working with gas.

 

35-37mpg is right on target for the Volt. Watch the ethanol content, the higher the lower mpg you will get

 

We always buy no ethanol premium which seems to give around 40 miles per gallon in CS mode. Regarding lifetime mileage, our leased 2012 (which I drive mostly back and forth to work all electric) is at 153 lifetime. Our 2014 is below 90 lifetime because we take longer trips. Oh well...

 

35.2 mpg on CS for 1800 gas miles of the total 26000 miles on the Volt. I live on a slight grade so every CS trip I do is uphill home.
You are doing well. How many ICE cars get 35?

 

Especially with a 500lb battery

 

Expect 35 mpg for normal driving. You might get 40 depending on winds, elevation, driving for best economy. I dont drive enough on gas, but lifetime average is 35 over 1300 gas miles (9000 EV miles).

 

I once saw a clip from the show Top Gear where they dogged the hell out of a prius on a test track. It got 17 mpg. So, smooth acceleration, smooth stopping, and watch your speed.

 

Low temperatures certainly are a factor - especially if you have multiple cold starts in the drive.

I didn't really notice a break-in period as such - but I do feel like there was a big step after the initial oil change, and tire pressure made a big difference.

The Volt uses three different strategies for under 36 mph, 36 to about 62, and over about 62 mph. You don't want to be in the under 36 block any longer than you have to (but you also don't want to accelerate hard.)

I'm still not quite sure if the 62+ is more efficient - but of course aerodynamic loads mean the car will be most efficient at slower speeds even if the energy conversion were more efficient at higher ones (and if it is more efficient, it isn't much different.)

I'm pretty sure the best achievable economy on gasoline would be at a constant 36 mph (on electricity the best speed is still lower) - but no one I know drives that way, and I'm not suggesting you should.

So as others have said, keep it gentle and smooth, and drive at the lowest speed that fits with your comfort and travel plans on the freeway.

 

Drove close to 3600 miles this part summer, unfortunately I did not have consistent charging opportunities regretfully. Most of the trip therefore was on ICE. I was averaging 65 mph and getting between a low of 41mpg in very hilly terrain and for most of I70 I was getting 45 mpg. Certainly far better than if I just used the ice for short periods here on the east coast. On short excursions 100 miles or less I average 37 to 40 mpg and slightly less during winter. But all cars suffer when the weather starts dipping into 30's and below.

 

I seem to get 34-38MPG most often when using the generator. It's best to use it when you can cruise for miles at a time at a constant speed, and best when you can use it for more than a few minutes. I find the first quarter gallon burned in one stint will be on the lower end of the fuel efficiency range... but it gets better if I have to go through a gallon all at once.

 

You said you cycled Hold on and off... I would suggest you don't do that. Engines are most efficient once they reach correct operating temperature. By cycling it on and off, you are spending less time at full operating temperature.

 

Tires are aired up to sidewall max but sometimes end up at 47/48psi.



I only did that one time and it resulted in the best fuel economy.

Normally I run on the generator for about 60 miles at constant speed with one 3 minute off period where I am driving through a town in the middle.

I end up with almost zero electrical miles at the end (or in some cases zero) and have my trip mapped very well.

I generally don't use AC or heat (except for engine generated heat when I need to defog)

All in all my trip should be ideal for volt fuel economy with a great deal of time spent right at 55mph.

Not really sure what else I could do differently and cruze control seems to have no affect, but then again I was an avid hypermiler so my foot is rock solid.

I will try driving by KW next time I do my biweekly trip and see if that has any affect.

Cheers
Ryan

 

My lifetime CS MPG is 41.6 according to VoltStats (CTSOLAR #34). In the summer it is easy to get mid 40's. I usually drive 62-63 MPH using cruise when possible. This allows the engine to cycle on/off when terrain permits. I do have one trick I use on a frequent weekend trip. This trip has a 7 mile climb. I leave home in mountain mode (2012 - no hold mode). I am in CS mode 10 miles before the climb. When I hit the climb I switch back to CD mode. The 7 mile climb uses 14 miles of estimated electric range. On the return trip I am in CS mode long before the decline. The engine shuts off when it hits the decline and doesn't cycle back on for at least 12 miles. The rest of the trip both ways is rolling hills. A summer average for this trip is 45-46 for the CS portion. In winter the ERDTT mode knocks the average down quite a bit. Tire pressure is 40 PSI. I run Blizzak snows in the winter.

 

You are right . . . under the conditions you describe, you should be getting better mileage. Have you checked the temp of your brake rotors at the conclusion of a trip to see if your brakes are dragging? Assume you:
1.) Don't have car loaded to the max
2.) Don't have a rack on the car
3.) Don't drive with windows open