Decent Highway MPG

How many gallons did it take?

 

Ditto. What was the "MPG?" Miles on a tank doesn't mean much without the other number.

 

I'd love to know what all you folks are doing to eek out 600-plus miles to a tank. I'm reaching 9K with a late 06 Prius and now that summer temps are with us in Central New York, my average MPG is 44-45. The best ever was 52 and in the middle of winter, with the car sitting out all the time in sub-zero temps, mileage drops into the mid-20 to low-30 range. From talking with other owners with vehicles dating to '05, the 44-45 range seems to be standard around here. Must be New York State with its undulating hills, long, steep hills, windy roads, Thruway travel, and normal temps. But I'm still intrigued with the seemingly off-the-chart numbers posted on this site. Question: Can you get 60-70 mpg while text messaging on one phone, receiving a video clip on another, eating a 4-course dinner, and driving with your eyes closed?

 

<div class='quotetop'>QUOTE(chuck kershner @ Jul 21 2007, 08:57 PM) [snapback]482986[/snapback]</div>

First congratulations Vince on your 600 mile tank, regardless of your gallons I long for such numbers just for the experience.

Chuck, just to give you some perspective re-read Vince's post and you'll see that he traveled 60 MPH from Texas to Ohio! There are definitely optimum speeds, conditions, and techniques to get the 600 plus tanks, but compare that with say CA, I just got back from business in LA, two 400 mile fill ups of 49 MPG going, 67 MPH (mostly CC), and 44 MPG coming back, return trip 75+ MPH, interstate 5 both ways. Posted speed limit of 70 MPH almost the entire trip!

My point is don't be chagrined, if you could manage 60 MPH on the freeway and 39 MPH on surface streets I would bet that you would get 600 mile tanks easily!

 

<div class='quotetop'>QUOTE(VinceD @ Jul 22 2007, 08:23 AM) [snapback]483129[/snapback]</div>

Your original post had the range that you drove, but not the MPG or the number of gallons that it took to refuel the car.
<div class='quotetop'>QUOTE(VinceD @ Jul 21 2007, 03:38 PM) [snapback]482915[/snapback]</div>

 

<div class='quotetop'>QUOTE(chuck kershner @ Jul 21 2007, 09:57 PM) [snapback]482986[/snapback]</div>

Nope! I can do high 50s/low 60s pretty consistently on my highway commute but it takes some effort. It doesn't require anything fancy but it does require paying close attention to traffic to avoid braking, keeping my speeds right around the limit, and glancing at my tach ($20 at Autozone) to keep the engine mostly in the "butter zone" between 1500 and 2400RPM. Sounds fancy but it keeps me focused on one thing: driving the car.

 

<div class='quotetop'>QUOTE(brick @ Jul 22 2007, 03:45 PM) [snapback]483245[/snapback]</div>

hey brick, just curious, at what speeds is your tach showing 1500-2400 RPM would that be, say, 29, 39 and 59 MPH, say level road? These MPH seem to be the sweet spots suggested by many posters, but I don't seem to recall anyone associating a tachometer range, hmmm ...

 

As always, "it depends." Speed limits on my commute are 55 or 60mph depending on which stretch, and most of the time I'm either headed up or down hill. I can usually maintain 60 on the ascents without breaking 2400rpm so. On a dead flat road with no noticeable wind, the engine seems to produce enough power to maintain 60mph when it is turning right in the range of 1500. On the down-hill segments I back off and employ a little "warp stealth" to stop fuel consumption until I have good reason to demand significant power from the engine again.

Keep in mind that the use of a eCVT means that the only relationship between engine RPM and steady-state speed is power output. In other words, the car will open up the throttle plate and then control power by increasing or decreasing engine speed. I haven't noticed any particular sweet spots except that the range between 41 and 50mph is a pain to manage. 1500RPM makes too much power for steady speed on a flat road so you have to use warp stealth to P&G, and that kind of P&G is a lot more touchy than below 41mph.

Now that I think about it those speeds do make sense as a general guideline. Below 40mph (39mph) the system will sort of P&G for you as it goes between gas and electric operation. At 55-60mph (59mph) you are moving fast enough that the engine can run at the low end of its efficient range and still hold roughly 60mpg from my observations. Above 60mph aerodynamic drag picks up and there is a fairly steep decline in fuel efficiency. By 70mph I don't expect to be much above 50mpg.

 

I'm still hopin' for my first 500-mile tank, just to say I did. I can't bring myself to hit the blinking pip, and so I've been at 475miles max, before feeling the urge to gas up!
But 630, without a blinking pip... figure anywhere from what, 10 gallons down? Comfortably middle 50s mpg up to mid 60s mpg, I'd guess. Then again, I've given up on the "replacement gallons" pumped in, as the indicator of just how much I burned on the drive!

 

<div class='quotetop'>QUOTE(brick @ Jul 22 2007, 08:55 PM) [snapback]483360[/snapback]</div>

thanks brick nice reply and a great lesson i think you've captured the gist of several threads very nicely.

 

Here is the best tip for getting excellent highway mileage (most of summer i have been in the upper 50's / lower 60's with about 70 % highway) its all about giving enough following distance so that you rarely (and i do mean rarely) have to even touch the brakes if ever while on the highway, that way as traffic patterns change on your trip you can coast to slow down to the new pace of traffic. My drivers ed teacher told me to give a good 2 car lengths for every 10 mph of speed and I discovered years ago that it has a great side benefit of better mileage as well as safety.

By applying this principal I can average 59 mpg at 55 mph, 57 mpg at 60 mph, at 65 mph I can average 54 mpg, 70 mph i get 52 mpg and at 75 mph I can still, but barely maintain 50 mpg.
Also remember to pick the speed that traffic allows not the speed you want to travel unless of course there isn't any traffic.

 

I've noticed that mileage goes down substantially with hills. I don't see many posts noting terrain or grade details. I live in the SF Bay area, which has a lot of hills but also flat areas out towards Sacramento, etc. Once I get out of the hills mileages is much better. I would have expected hills to 'balance out', where energy gained going down the hill makes up for energy lost going up the hill, but this doesn't seem to be the case. Or maybe its just really difficult to optimize the acceleration up the hill to get it right. I live on a pretty steep incline, so if I make a lot of small trips back and forth up my hill, my average reading steadily goes down. I wouldn't be surprised if those reporting high MPG live on flat terrain.

 

<div class='quotetop'>QUOTE(wanderingBrian @ Aug 3 2007, 01:18 AM) [snapback]489808[/snapback]</div>

Yes you are correct, for the most part it is pretty flat here in Ohio.

 

On the trip from Elkhart, IN to Madison, WI for Hybrid Fest, I averaged 71.2 mpg. On the trip home, I averaged 72.5 mpg. My current tank is at 83.7 after 522.9 miles with 6 pips showing.

 

<div class='quotetop'>QUOTE(berylrb @ Jul 22 2007, 08:04 PM) [snapback]483320[/snapback]</div>

Just a side note. Any speed 41 MPH and up the ICE is running at about 980 rpm.(more if it requires more power) I believe this is to prevent MG1 from overspeeding. Even though the engine icon on the MFD shows that the engine is not producing power to the wheels..even in warp stealth as it is called... my scanguage II still shows it running at 980 rpm. There is no doubt when the motor shuts off because the SG II rpm goes to 0 rpm and I usually physically feel that the engine has shut off when it has a slight shutter. Hope this helps and is useful for FE. I believe the most efficient mode is a pulse to near 40mph not to exceed 40 and glide to 32-33MPH. Repeat untill fillup is required. Anything above 45-50 MPH is a large strain from windage losses(drag)