POLL : what MPG are you getting in your gen 3

Seem like very good numbers for the 3rd gen Prius. Too bad I don't have one.

 

I'm in Canada so the car reports my mileage in litres/100km. For convenience, I'll translate these numbers over to US mpg.

Most of my driving consists of a 106 km round-trip commute to-from work, nearly all of it on the highway. The drive is in made during rush hour, so it often takes about an hour or more to drive the 53 km distance. I think this is probably the ideal situation for attaining maximum mpg from the Prius.

I reset trip-B when I fill up -- currently there's about 670 km (415 miles) recorded, with a projected empty at about 940 km (585 miles). The display reads 3.4L/100km (69mpg), but I think that's about 6 - 10% optimistic on the car's part, so real-world mileage is likely closer to 3.7L/100km (63mpg).

Currently, I'm resetting trip-A for each leg of the trip (i.e.) every 53 km, so that I can quickly judge different driving techniques. The car shows a bit better mileage on the drive home -- I've been able to record 3.1L/100km (76mpg) twice, while the best I've been able to show going to work is 3.4L/100km (69mpg). But the drive is a bit longer coming home (traffic is heavier in the afternoon and the car rewards you for driving in heavy traffic), so that might account for the difference. Most of the time the air conditioner was off, since it's been fairly cool up here in Canada so far this year.

It's interesting to watch the display when I reset trip-A, since it shows the cost of warming up the gasoline engine. Typically during the first 5 minutes, it reports anywhere from 6.8L/100km (35mpg) all the way down to 9L/100km (26mpg). It takes me more than 15 km (10 miles) to bring my mileage back up to the 3.4L/100km (69mpg) point. So you can see why people with short trips get less than perfect mileage.

Initially, I tried to keep the car on battery as much as possible. While this technique reported an excellent mileage of 3.4L/100km (69mpg), I decided that I didn't like the fact that the battery kept cycling down to 2 bars, since I think this places a bit of strain on the battery and might reduce its service life. Also, I'd read that pulling energy unnecessarily from the battery results in slightly reduced overall mileage, due to electrical conversion losses. So I decided to drive the car a bit harder to get it to ignite the gasoline engine a bit more often. Since this also helps me keep up with traffic around me, it seemed like it might be a win-win scenario. So far this is working; the mileage is the same as before, and my battery rarely goes below four bars now.

Surprisingly enough, rush hour traffic tends to support the pulse and glide technique that's so often discussed in here, because heavy traffic automatically pulses (although sometimes the pulse is a bit more than I would want). So when traffic surges, I allow it to build up a bit of space in front of me before I accelerate, and when I do accelerate, I watch the HSI screen and try to to position the bar to the far-right, just left of the PWR section. As I begin closing on the car in front of me, I take my foot off the accelerator and allow the Prius to coast up to it. This results in a bit of regenerative charging (the HSI bar enters the right part of the CHG section), but this regenerative drag is small enough that I don't worry about it (and I think that periodically feeding a bit of energy back into the battery might actually help improve its service life). The idea is to time this so that you mostly won't need to brake as you coast up to the car in front of you. Of course, you won't be able to do this every time, but I've found that I am able to do it about 50 - 60% of the time. And even when you do brake, the car will recover most of the energy, so the odd miss is not serious.

Initially I ran the car in ECO mode, and lately I've tried running it in normal mode. I found that, at least so far, I can get the same mileage in both modes. I'll probably try running it in power mode:rockon: soon to see if that makes any difference for me (from a fuel economy perspective, that is).

 

While technically true, the difference is infinitesimal -- even more so when you consider gas stations store their fuel in double walled undergound tanks. Whether it's not or not coming from undergound, the point is the DIFFERENCE in temp. expected from morning to afternoon to night.

Apparently I can't yet post website links so:

www-hotfuelishotair-com/resources/view/4/file

 

I have just over 2000 miles on my Gen III and the best I have seen on computer for a tank of gas is 44.7. Current tank seems to be dropping off for some reason, showing 40.5 on about 190 miles of travel. I don't know why it's dropping off, same routes and driving style. I have hard time believing the 50+ mpg reports on here.

Also, computer mpg is about 2 mpg higher than manual math.

 

Have you added weight to the car? Checked air pressure in your tires? Have there been any weather changes? Each of these could account for the 4MPG difference.

Read a bit more on the PriusChat site about how to increase your fuel economy. Look at the Sticky threads in the Newbie forum (and others).

And good luck to you.

 

Will probably fill up tomorrow (1st time) at 600 miles on the odometer. Will save the final tally for report later. Yeah, I'm driving fairly conservatively but I only have a 1.8 mile commute to work and so a lot of my driving is in warm-up cycle.

Just to see if I can replicate your results, I'll drive like an absolute crazy maniac, flooring all acceleration every time and especially during the warm-up cycle, deflate my tires to 5% below MRTP (don't want to set off the TPMS) and run the A/C full blast all the time with the windows wide open. Not sure if I can get less than 40 but I could give it a shot! I'm not saying you drive like this but I don't know how else to go that low.

 

Finallly bit the bullet and bought my first tank on the way to work this morning. No idea how much dealer put in but assumed it was full. When I took delivery it had 11 mi. on the ODO. Never adjusted TRIP A at delivery since Trip A also had 10.7 miles at the time.

First tank - 605 miles, took 10.795 g, so calculated at 56 mpg. Interestingly, Trip A MFD said 56.3 so not that much variance yet.

This was almost all in town driving, short trips. I'm happy!

 

Today's update; I filled the tank, did the math, mpg a lousy 39 and change. Maybe I have had the lead foot this tank. Anyway, I drove very carefully the 25 miles home (mostly hwy), no crusie control. I monitored the mpg gage and tried very hard to keep it at 50 or higher. If it started dipping, I eased up on pedal to bring it to 50 and sacrificed some speed until the next down hill where I tried to build speed back up yet maintain 50 mpg or better. I was able to maintain 57 to 58 mph most of the time but had to slow to 48 or so a couple of times. Bottom line, computer said 54.1 mpg so far on Trip A @ ~ 25 miles. Thats a world record for me.

Thanks for the previous responses and driving tips.

 

Ga, I'm sure there are many drivers on here better than me so take this as "what works for me". Try releasing the accelerator pedal abruptly. This action will get the display up to 100mpg, then feather the accelerator pedal to maintain speed. I find that once your mpg display reads less than 50, it will be very hard to get it back up to 100 unless you are going downhill. Again instead of waiting for a downhill, just release the accel pedal abruptly and u re good to go.
Good luck

 

Here's my data:


.

 

John, Interesting your graph shows a declining trend? I only have 3 tanks so far in this prius, and my fe is improving, (breakin or learned the car) I'm wondering if I will have results similar to yours. Did you have any circumstances (other than summer temps) that you feel caused the downward trend? BTW I have mine for 6 weeks and am getting your current mpg 54-56.

 

I'm nearing the end of my 2nd tank of gas, and I'm getting about 47.5 mpg. My first tank was just above 45 mpg, so it is improving. I hope the posts I've seen about it improving even more over the next few tanks are correct.

My commute is about 80% on a tollroad at 75 mph, with AC on all the time (temps are 80 in the morning and 100+ in the evening), so I'm not unhappy with my results. They are close to the EPA of 48 mpg for highway, and I can see the average climb on the areas when I'm in city driving. Considering the constant AC use and high speed (my average speed readout is around 40-41 mph, whereas I've seen a lot of posters saying theirs is around 27), I think I'm getting really good results.

I've reset the trip meter during different segments of my commute to see how the mpg differs, and I get 53+ in urban areas (not downtown, but residential areas with stop signs and occasional lights) and around 46-47 on the highway with CC at 75 mph.

I'm hoping cooler weather and few additional break-in miles will get me up to the coveted 50 mpg average.

Forgot: I haven't checked the tire pressure yet, so that may be having an effect too. I plan to try the recommended 40/38 if they aren't already at that level.

 

John's data is consistent with what we saw in the early fleet studies as well as one traction battery replacement. My battery studies suggest that new traction batteries have a significantly better charge-discharge efficiency that degrades in the first 4-6 months. Thereafter the traction battery efficiency appears to remain constant for years.

Bob Wilson

 

I was noticing the same thing with the battery. On my first 60 miles home from the dealer, I had an opportunity to EV till the battery was nearly depleted. I did not make measurements but the distance far exceeded what I normally go in the NAH I'd been driving. (where the NAH normally ran out of juice, the prius was still at half charge) The charge and discharge cycles appear to have normalized now with approx 1600 miles.

 

Odd. When I try, I can usually get between 4 and 4.5 l/100 km on the first 5 min block by P&G'ing a bit. How far does that first 5 minutes get you? When you leave, what is usually the charge level of your battery?

As far as the 'keep the battery level high to prolong service life' goes, the Prius does that by itself. When the battery monitor shows 2 bars, it is far from empty. I believe the HSD does not deplete the battery below 40%. Perhaps you're worrying a bit too much.

 

So far, I've only filled up twice (1000 miles in only my first week), and have averaged 55.5 in mixed hilly highways and rush-hour freeway driving. Not too bad, I think -- definitely better the truck I traded in. :rockon:I've found that with a bit of right foot training I do better without the EV mode, but douse EV occasionally. I haven't quite figured out where it makes the most sense yet.

 

At 3,200 miles I'm getting 50.5 mpg, based on calculations of gas in the tank. Driving has usually been with A/C on in normal mode.

On our 2700 mile trip -- Ohio to Maine, to DC, & back to Oh, we averaged 50.9 (computed), with the trip computer reporting 53.4.

In the forum, we talk a lot about driver-to-driver differences (for good reasons, I think). Is it possible that there are reasonably large vehicle-to-vehicle differences too?

 

First full tank was 49.2 mpg, assuming dealer filled it all the way up, of course. The HID estimate was 55 mpg. Guessing the real number is somewhere in between and hopefully goes up a bit as we learn to drive better and break-in the powertrain.

 

I have a general commute of 30 miles one way to work; first few tanks were based on not having the NY State Clean Pass and the later ones allowed me to go on the HOV lane. Considering the general hot weather of the summer, the occasional short trips I take from time to time, and getting used to knowing how to drive the car (which is different from the old Gen I model in a number of ways) my MPG has been from a low of 46.6 to a high of 49.2 (based on the fuel tank not the display numbers which are above 50). I have 8 data points so far. I should know more when the weather becomes better and I have a few really long distance trips recorded (one is coming in October).

 

I had been using the numbers from this poll to track 2010 Prius MPG:


Bob Wilson