Just One Type of Driving Scenario

[HPRifleman]

A lot of us talk about the mileage we get with our cars. Some seem to be doing great while others wonder how anyone can get reach EPA. What we can't compare very well are the routes that we are driving. So I thought I would drive the same route every day and record my mileage for each trip.

This is my daily commute so each mileage value is either coming home or going to work. Each trip consists of the following:

0.5 miles - Residential streets with a 25MPH speed limit.
3.5 miles - Suburban 4-lane roads with stop lights, strip malls, and traffic. 45MPH speed limit.
3.0 miles - Rural/Forest preserve 2-lane roads. 40MPH speed limit.

Total one-way distance: 7.0 miles
Almost all of this commute is on flat land with minimal elevation changes. There are 9 stop lights and 2 stop signs. Fuel was 87 octane unleaded and climate control was not used.

While the lower speeds play to the hybrid's strengths, the low total miles mean the car spends a larger percentage of the drive warming up the ICE as opposed to a longer commute.

Trip MPG:
52.2
59.2
46.1
50.4
48.2
56.7
65.0
51.8
53.3
56.9
54.3
57.1
50.0
56.9
46.1
60.3
56.3

Min: 46.1
Max: 65.0
Ave: 54.2

As you can see the mileage over the route can vary greatly. The route was the same and I like to think I drive fairly consistently. What I can't account for is other traffic and the amount of stops I will have to make. Some days I can breeze through green lights while other days I have to stop several times. Each stop means that I will have to engage the ICE getting back up to speed while constant driving allows uninterrupted Pulse & Glide.

I don't really have a point posting this information except to maybe clarify one type of driving that can achieve good mileage numbers. I would like to hear from people who drive under similar circumstances to see if you get similar mileage (or worse or better).

[homestead]

Any idea what the state of charge you had on the hybrid battery for each of these trips,  that may help explain some of the variations.

[HPRifleman]

The state of charge will vary over the course of the trip. When pulling out of my driveway (in the residential part) there may be enough charge to get me through the 0.5 miles in electric only if I go slowly enough. Usually though the ICE comes on before I get to the end of my street and the first stop sign. Coming home the 0.5 miles is always covered using EV+ so that is 999.9 MPG.

 

On the other two portions the state of charge will very greatly with how often I stop. This is because if I stop and have to accelerate back to speed I will be recharging the batter at the same time. If the lights are green and I can keep moving I will stay in EV longer and the battery stays in a lower charge state.

[hybridbear]

A lot of us talk about the mileage we get with our cars. Some seem to be doing great while others wonder how anyone can get reach EPA. What we can't compare very well are the routes that we are driving. So I thought I would drive the same route every day and record my mileage for each trip.

 

This is my daily commute so each mileage value is either coming home or going to work. Each trip consists of the following:

 

0.5 miles - Residential streets with a 25MPH speed limit.

3.5 miles - Suburban 4-lane roads with stop lights, strip malls, and traffic. 45MPH speed limit.

3.0 miles - Rural/Forest preserve 2-lane roads. 40MPH speed limit.

 

Total one-way distance: 7.0 miles

Almost all of this commute is on flat land with minimal elevation changes. There are 9 stop lights and 2 stop signs. Fuel was 87 octane unleaded and climate control was not used.

 

While the lower speeds play to the hybrid's strengths, the low total miles mean the car spends a larger percentage of the drive warming up the ICE as opposed to a longer commute.

 

Ave: 54.2

For such a short mileage commute you get really great mileage!! I would expect that your MPG will tank in the winter though :( on such a short drive in the winter based on our experience last winter with our FFH you will likely see at least a 10 MPG drop if not more.

[fbov]

I'm doing something similar (recording consistent round trips) using a ~15 mile route, and will post results when I have enough data to say anything. The first thing I see is a temperature effect. Try adding the outside temp and perhaps a special weather note as I expect both of these to add variability to the data, no matter how consistent your driving style. You may also want to group in round trips, as that takes net elevation change out of the picture. Mine are in pairs.

 

Have fun,

Frank

[ScubaDadMiami]

Your SOC will start at different levels, giving you either a starting advantage or disadvantage. That could be the difference. Then, there are the other factors you mention, such as how the traffic varied, and how you hit or missed the traffic lights.

Edited September 10, 2013 by ScubaDadMiami

[HPRifleman]

I have found that it is more traffic and stops than SOC at the beginning of the trip.

 

Having a high charge on the battery is not a great help in a residential area as the speeds are low and you burn up that charge without a lot of miles to show for it. Being able to cruise through green lights and not having to push hard because the guy behind me wants to go 10 over the limit are much bigger factors.

 

My commute is only 7 miles. As many of you know, a longer trip with 40-45MPH speed limits will greatly raise mileage. Sometimes I have had to run errands after work which drag the overall trip to 15 or 20 miles. In those situations 60 MPG is not difficult to achieve.

[CMaxChat]

I have found that it is more traffic and stops than SOC at the beginning of the trip.

 

Having a high charge on the battery is not a great help in a residential area as the speeds are low and you burn up that charge without a lot of miles to show for it. Being able to cruise through green lights and not having to push hard because the guy behind me wants to go 10 over the limit are much bigger factors.

 

My commute is only 7 miles. As many of you know, a longer trip with 40-45MPH speed limits will greatly raise mileage. Sometimes I have had to run errands after work which drag the overall trip to 15 or 20 miles. In those situations 60 MPG is not difficult to achieve.

Is there an elevation change as Frank mentioned?  It can make a big difference.  It would be best to keep data on the roundtrip to rule out elevation as a factor.  It would be interesting to see how much temperature affects mpg.  It is interesting to see how much it varies though.