The Can't Get Above 40's Club

My Prius is still new - as I am to this forum and learning proper driving techniques. With about 440 miles so far (just bought my first refill tank), the best I've seen during solo highway driving (65mph) with the AC off and the CC on has been about 51mpg. In mixed city driving with the AC on, it's been around 36mpg. Averages are usually in the low-40's range, with the AC mostly on and little regard for special technique. I look forward to improvements with break-in and experience (I've still got a LOT of reading to do around here).

(BTW, how did the EPA, which I expect to get mpg somewhat optimistically wrong always, get this particular car so spectacularly wrong? Too unfamiliar a technology I guess, except that you'd think the first gen experience would have taught them something about reality. Maybe it's just deliberate misinformation as policy, to encourage hybrid sales, though in a way that seems not cynical enough for the feds...)

 

i am not that far off and my mileage especially surface street driving is rising.

in fact, my freeway driving exceeds the EPA estimate of 51 mpg. i am averaging just under 53 mpg.

in the city, my average was at 49.6 initially, but its now consistantly above 50 mpg and a few things ive started doing lately ive noticed, have seemed to help. one is using the B mode more often for slowing the vehicle down when coming to a stop.

but my lifetime average is now 52.3 mpg and i feel that it will get better. driving technique without a significant change in the overall speed you drive at will add at least 2-3 mpg. i also believe that breaking in the car will add about the same. so i think i will be very near to the EPA average of 55.1 mpg in a years time.

as far as coasting frequently and trying to time the lights, heck i started doing that in my Ford F150 in a useless effort to try to save gas money. with the way the vehicle idled and the fact that it idled all the time, i probably didnt improve much on mileage at all. iow, another less publicized caveat to the Prius is the fact that the vehicle does show a measurable improvement in economy when the driver takes proactive stance to increase the mpg. My Ford didnt.

 

One note I've seen in *several* places is that Prius mileage improves significantly over the course of the first few weeks and months of driving. A new car has a lot of extremely stiff, tightly-fitted, un-broken-in parts that require more energy from the power plant to actually set in motion. As the car loosens up, it actually becomes easier to propel, as well, improving efficiency!

 

With summer here, I get low to mid 40's. I drive it exactly as I would drive any other car, except that I put it in EV mode for parking lots or short trips of just a few blocks, and I drive gently in EV mode so as not to pop it out of EV. My normal commute is 4 miles. I figure I'd be up around 50 or more if I had a 15-mile commute. I also get low-40's at 75 mph (freeway speed limit in ND) but I get 50 mpg at 55 mph (country roads). I figure I'm getting what I should get under the circumstances, and I highly doubt that the egg-on-the-pedal method would make much difference for me, as long as I'm mostly driving 4 miles.

I just filled up for the first time since installing the EV switch. I'll be interested to see if my mileage improves (or falls).

 

yep short trips are what kills my mileage too. i commute only 11.5 miles to work but i do have lots of occasions to take longer trips.

 

Daniel,

I realise you're not actually complaining, but your post did put me in mind of how jaded people can become. One of the most common whines I see in the press is how their tests net the Prius an mpg that's 'only' somewhere in the 40s. Meanwhile, until I get my Prius, my Forester is getting anywhere from 18 to 25mpg (last week's really hot weather killed my mileage, altho' I'm also suspecting the 'bad gas' theory for part of it). In other words: mid 40s? I'll take it! :-D

 

My old Civic got 35 mpg. So low 40's is not what I had expected.

However, it's apples to oranges, because most of the years I had the Civic I lived out in the country, and I tested my mileage in summer. My driving was 98% highway. Six miles to the nearest small town. Thirty miles to Fargo. Now my commute is 4 miles, and occasionally I go to the shopping district 15 minutes away.

And when I got my Prius, I had not yet found any of the Prius discussion boards, and the dealer played up the mileage and joked about buying gas once a month (which would be 1,000 miles to the tank for a 12,000-miles-per-year driver!). I knew nothing about (and the dealer did not mention) the effects on mileage of cold weather and short trips. I didn't know (and the dealer did not tell me) that the mileage is much lower during the warm-up period, or that running the heater full-blast (this was January) would essentially force the ICE to run continuously.

I now believe that my car is performing up to specs, and that it gets double the mileage of any conventional family sedan under the same conditions. But I also believe it's reasonable for people to complain when dealers conceal information from them. But we are the pioneers. We are producing the information for the buyers who follow. And we have a responsibility to promulgate accurate information: that the Prius can attain the EPA figures, but only under ideal conditions, that most people will not experience.

 

My comments expressing surprise at the EPA mileage figures mostly has to do with their assumption that city MPG will be significantly higher than highway MPG. I have seen the reverse.

But I too am not complaining at all about getting results in the 40's, high or low. And lately, as the car has been breaking-in with over 1K miles now, the overall number is getting much closer to the 50 MPG mark.

I'm interested to learn that I can expect lower figures when the weather turns colder. I thought that one of the reasons my recent mileage has been improving was because it's been a bit milder around here than it was earlier in the summer. Not only can I turn off the AC more of the time, but I assumed that the ICE works more efficiently with a cooler air intake temp (cooler = denser = more oxygen per unit volume). But I hadn't thought about the heater requiring more ICE run time (kinda like the AC).

 

to get a good idea of how your mileage will be affected. try taking short trips of 5 miles or less. what you will see mimics the mileage you will get in cold weather. however, i suspect that longer trips will be affected much less.

i commute to work 11 miles. my best guess is that i get about 46-48 mpg on those short early morning trips. (i have to be to work at 5 am so its headlights all the way now.) also you will notice on the comsumption screen where the bar graph denotes mpg in 5 minute increments, that your first bar will always be significantly lower than the rest of the trip.

another factor to consider is that winter mix gasoline isnt as powerful. the mix is necessary to reduce freezing. the cost is power and its reflected in lower mpg.

 

A friend of mine told me yesterday they noticed a definate increase in mpg when their car turned over 10K. I suggested a race to her house, the one with the highest MPGs wins I think Evan started noticing it about 8K.

I averaged over 51 mpg on 99% highway - ~425 miles Thursday on the rental (just over 5K miles) .
I reset the meter Friday night so I could see how it did "city only". I went back and forth to the ice rink (about 7 miles 1 way) 4 times this weekend because we were having our annual skating competition. Temps 70s to 90. Every trip had many hours of "parked" time before I drove it again, 2 of those were overnight. In general, it averages downhill to the mid point, then uphill to the end. No long or steep grades, but there are a lot of little ups and downs all the way that require ICE to maintain speed. Roads are posted 25-30 mph, 16 potential stops (lights or signs). I was making an effort to maximize mileage by using stealth, or generating max amps if the ICE was running, when possible. I got it up to speed as I would in my Odyssey, I just made use of the "below 42 mph" capabilities of the car. The avg after this was about 47.5 mpg.

One of my daughter's friends came home with us Sunday afternoon. We went out to eat then took her home. This trip was a few miles of 55 interstate, the rest 35-40 with some lights and represented what I would consider more my usual driving. However I wasn't driving. My wife and I each have our "own" cars but sometimes do switch and if I'm going to get one, she has to at least be comfortable in both front seats. So I let her drive "My ;-)" car. With a little instruction from me (she didn't mention divorce, so I guess I wasn't TOO overbearing) we got home with the trip meter reading 77 miles since Friday night, all but the top 2 battery bars (and they were green), 49.3 mpg average. I'm letting her take it tomorrow so she can see the interstate side of it as she is going to her parents in Stowe - 25 miles of 65 interstate and 15 miles of 35 - 50 mph, all uphill. I'm not expecting to hear about how great the mpgs were when I get there later in the day! I should get MUCH better mileage when I drive it back home Then, :-(, I have to give it back to Enterprise Wed AM.

 

OK, this car is amazing. The car started yesterday with 15 miles - 51.7 mpg from my Monday commute. My wife drove it round trip to the rink - 15 miles, then to Stowe. Add in one round trip from the in-law's to Little Spruce, and another over the Notch "mountain driving" test including a demo of "no downshift" hitting it hard up hill. Not a lot of miles on these 2 but it's either "power from all sources" or "regen in B mode while riding the brakes" driving. Performance was well above adequate. Yes, the mileage dropped ... to 48.7 on 107 miles. WAY better than I expected. Got home with 145 miles, 51.5 mpg.

Sadly I have to give it back in an hour. But I'll be getting on the lists. Hopefully the 50% production increase announced yesterday will make my wait less than the expected 6-12 months.

 

I have been averaging 45 mpg but the last two tanks have each fallen below 39mpg. Nothing different in my driving, weather only slightly cooler. Any suggestions other than what I've read above? My tires are 40/38. No A/C.

 

winter blend fuel?

 

First tank: 47.9 mpg, second tank: 53.3 mpg on a new 2005. The trick is to anticipate what is ahead (stop light, congested traffic, intersection) and "feather the accelerator."

I do a 45 km (30 mi) commute each way each day (daily total 90 km or 60 mi). One-half on highway at 65 mph, one-half on a parallel highway that has less traffic and allows for slower speed. The odometer is approaching 1k, so I figure the fuel economy is correct.

At the end of each 45 km (30 mi) segment, I have all but one green bar.