A question about driving routes (no, I haven't lost any sleep on this subject !). What do people think about the choice of driving routes ? I have the choice of : * using the motorway (freeway) for a quicker drive, and have a higher fuel burn rate. * use the streets for a slower drive, but have a better fuel economy. The time difference isn't much, sometimes only 5 minutes more. Othertimes the streets are packed and the journey can take double the length of using the motorway. So there I was, sitting at a read light in a totally quiet car, pondering the question - is it better to go this way and take longer ? Or go quicker but have a worse fuel economy.
Re: Driving routes : quicker and worse mpg / slower and bett highway. i commute on it daily, averaging 85-90mph, and i routinely get about 49mpg, sometimes 50mpg but rarely. It's been hovering under 45 or so lately due to max A/C usage.
If the time distance is about the same then the highway distance has to also be a factor. I've made use of the NAV to save miles on my commute. For the sake of argument, It seems to me that a 20 mile drive at 75 MPH with MPG of 50 uses a lot more gas than a 15 mile drive at 45 MPH with an MPG of 45. When you save 5 miles on your commute, you are saving a lot of gas. So you can't go by the MPG by itself. Personally, I get much better MPG at 45 than I do at 75. So when I drive shorter as well as slower on the back roads, I'm saving a lot of gas. Of course, that's on my way home. On the way into work, I take the highway because I prefer those extra 3 minutes in bed. Plus, I hate stop and go traffic. So this is another reason I take the highway in the morning. There is less traffic in the evening on my back road route, not so in the morning. And I see all red lights as a challenge. I love trying to still be moving when I reach the lite as it is turning green. I'm getting better at that.
Re: Driving routes : quicker and worse mpg / slower and bett This would be only an approximation, but try the following. Note the miles and MPG on the consumption screen at the beginning and end of the trip. If you divide the miles by the MPG, you get the amount of gas used for that many miles. The difference would be the amount of gas used for the trip. Try this over several trips for both routes and see how the amount of gas used compares. The most fuel efficient route is the one that uses the least gas, not necessarily the highest MPG.
Man, I never got 50MPG over 70MPH. I wish I lived in one of those lower-gravity parts of the country...
MikePaul - don't know why you don't, I typically get about 52-54mpg in my '02 at those speeds. As to which route to take there are more issues than just mpg. As another poster said what is the total gas consumption - as more mpg is not better if you also do more miles. But I think another issue is your time - what is the value of your time for the extra time it takes to go on the surface streets. There is no best answer for this - each person will likely come up with a different algorithim to determine which route they consider best when you factor in all the issues.
Re: Driving routes : quicker and worse mpg / slower and bett I thought that too, but I guess I was meaning is it better to go quicker for a shorter time or slower for a longer one. The motorway journey is slightly further in distance, as I have to drive in the opposite direction to where I want to go to get to the on ramp. The street way to work is at least in the general direction of where I want to go, there's just lots of traffic lights, etc. Bah, I just love driving the Prius though ! Jumped into my old car today to drive (Honda Accord) and boy did it feel weird.
Re: Driving routes : quicker and worse mpg / slower and bett It would have to depend on how bad the traffic is on the surface streets for me. While I'm still a Prius newby (will have to get my first fill up tomorrow), so far I've noticed that I get much worse MPG sitting in stop and go traffic then I do on the highway. On a Saturday full of stop and go traffic and many errands, I averaged about 27 MPG. On the highway, probably about 48 MPG. If the highway adds another 5 to 10 miles over a 40 mile trip than I should still do better on the highway (40/27= 1.49 gallons v 50/48= 1.04 gallons.) Did my first long drive up Rock Creek Park, instead of across the park (up and down the valley) and got incredible mileage, much of it EV only. Cheers, Jeff
Re: Driving routes : quicker and worse mpg / slower and bett In nice weather I can take back routes and get better mileage. But in hot weather the faster way is best because the AC load burns gas and it can be a large percent of the gas to move the car if going slow.
"highway. i commute on it daily, averaging 85-90mph" Yikes! I ignore MPG when choosing a route. I choose on convenience and safety. I avoid the freeway when coming home, even though it's shorter and would give better mpg. There are too many inattentive morons on that stretch, and I value my life more than my gas.
You didn't say if the distance was any different on the motorway versus the streets. Assuming there is a distance difference..... Driving 50 miles at 45 MPG (Speedway) uses 1.1 gals of gas. Driving 45 miles at 50 MPG uses .9 gals of gas. If this is a one-way trip for you, then you save .2 gallons of gas each way, or .4 gallons per day. Two gallons in a week, over 100 gallons each year, At $2.50/gallon, that is $250.00 in annual fuel savings. Assuming there is no difference in distance.... The slower route will save you gas...the amount depends on the distance you drive. As one mentioned before, you might want to calculate the value of your time each day. ...Or maybe I'm all wet! RJG
Me neither! I get closer to 45. Heck even at 60MPH I do only about 50MPG. I recall a poster factoring how fast he was going to go on a trip. He figured the 5 bucks it would have cost him to go 75MPH versus 55MPH was worth the time saved. So, factor time saved versus fuel/cost saved and decide from that.
i think the slower street route is better IF you can drive it with few stops. if not, the freeway will be better for you. the rate at which you burn gas shouldnt be the determining factor. go by how good you are at driving efficiently.
Re: Driving routes : quicker and worse mpg / slower and bett I've also read before about people driving 70 mph and being able to get 50 mpg. When I go 65 mph I generally get 52 mpg at best and sometimes 48. But if temps were 100 or above and I drove without AC I think it might get to 50 mpg in flat areas, driving at steady speed.
If you want to minimize fuel used then try to stay below 42mph. This will run in MG mode at constant speeds. Also, learn to brake in a "linear" fashion (light-CONSTANT pedal pressure, not excess pedal pressure just before you stop). I've found this linear braking seems to capture the most energy(don't do this with people behind you-you'll start braking twice as far from your stop as most people expect). If you want the highest ratio of speed/mpg then drive about 54mph for about 54mpg.
