Short trips, how much will it affect mpg?

You will get slightly less MPG with short trips. Thing is, you still can not get better mileage from any another car, except an EV. The Gen III gets better than the V, which is reporting low 40's. Check them out and good luck.

 

Yep.

Take a look at the results at Most fuel-efficient cars and Best & worst cars review, fuel-efficient vehicles. Be sure to compare the city results of the Prius to non-hybrids there.

From the description of CR's city tests on the last page of http://www.consumersunion.org/Oct_CR_Fuel_Economy.pdf, those look like short trips to me. The government test descriptions are that of the old (prior to model year 08) EPA tests and don't include the 3 extra tests that were added starting w/MY 08. For more info about the EPA tests, see http://priuschat.com/forums/other-c...uth-about-epa-city-highway-mpg-estimates.html.

 

Cindyh1 – It is not the shortness of the trips that erodes the running MPG average, as much as you having to go through the “fuel thirstier†Start Up/Warm Up Cycle every time you start a “Cold†Prius 1G, 2G, 3G or Vee Prius. During the time period of Start Up/Warm Up Cycle, you are essentially driving a conventionally-powered Toyota Corolla with a 1.8-liter I4 engine, and getting the same instantaneous miles-per-gallon fuel economy it would be during your “take my daughter to school and pick her up.. 5 miles there, 10 round trip..†(i.e. EPA MPG 28 City/35 Highway).Of course, after your “Cold†Prius warms up (~5-minutes±) you would be no longer driving on that 1.8-liter Corolla fuel economy profile, but rather on the 1.8-liter Prius Sedan Hatchback EPA 51/50/48 MPG or Prius v Station Wagon EPA 44/42/40 ICE profile.

Every car, whether conventionally-powered or hybrid-powered, has to pay the “Cold Start†penalty in instantaneous MPG (iMPG) during the period of “Choke On Operation.†A “Hybrid $mart†driver learns to “Stay Out Of The Way Of The HSD†during warm up, to ameliorate this “Cold Start Hit†to fuel economy, and not add to the fuel consumption the Hybrid Synergy Drive (HSD) requires to motor your “Cold†Prius down the road until it turns into a “Warm†Prius.

I invite you to read and digest section G. "ICE" COLD START/RESTART in my 10 Hybrid Basics & Best Practices Tips Guide To Prius Ultra High MPG. It discusses the what, why for and how to minimize this “Cold Start Hit†on MPG.

 

When the outside temperature is less than 40F, for the first 6 minutes/3 miles I'm getting from 22 mpg to 33 mpg on my 2010 Toyota Prius III. My mileage initially is very low because the Prius runs the ICE hard to warm up the catalytic converter and recharge the batteries. The warm up cost can be reduced if one pre-heats the Prius with an engine block heater (EBH) - but this is normally not sold on vehicles south of Canada. When I drive the Prius longer than 14 miles/50 minutes I normally can get the car up to 50 mpg or better. The Prius FE can drop dramatically in the cold. For shorter trips a lighter mild hybrid, e.g. the 2011 Honda Insight LX, or an economical diesel, e.g. 2010 VW Jetta TDI Sportswagen, or an electric car, e.g. 2010 Nissan Leaf, might get better get better fuel efficiency than a full hybrid like the 3rd gen Toyota Prius/Ford Fusion Hybrid/Ford Escape Hybrid. A 2nd gen Toyota Prius has a Coolant Heat Storage(CHS) system that can keep the coolant warm for a short time so that if you make multiple small trip in sequence where the time between each trip is less than 20 minutes there is only a small warm up penalty(to run the coolant pumps) for each succeeding small trip. The 3rd gen Toyota Prius has a more efficient warm up system but it doesn't have the CHS so it loses coolant heat more rapidly and therefore can be less energy efficient than the 2nd generation Prius in this particular scenario. You might want to consider a used 2nd generation Prius that is in relatively good shape...

 

Cindy, are you asking only about fuel consumption during the break-in period or in general for short trips.

I bought my Prius in June 2009. Despite being on flat roads and being cautious about my driving habits, initially my MPG was in the low to mid 40s. 400 miles later it had hit around 50. My dad drove it mostly for those first 400 miles and I don't know what his habits were -- it could hit the normal range earlier.

Where I live now, my commute to work is approximately 4 miles one way/8 miles round trip with several hills and 7 or 8 traffic lights in between of which I have to stop at 5-6 most of the time. Often times the car sits for 12 hours to more commonly 24 hours between the outgoing trip and the return trip. If I go grocery shopping it is probably a similar distance to the store. So not much driving/driving time (10 minutes door to door). Despite these conditions I am usually able to get around 52 mpg in the summer. Now in the cold weather I am in the 45-46 mpg range. I'd like to see a conventional car give you those readings.

So long story short, you'll still get great mpg values. If you are the type that practices hypermiling, I'm sure you'll do even better.

 

I doubt you'd drop into the 20s. I think you'd have to work very hard to get into the 20s, even with your driving profile. I could see you maybe dropping into the mid to upper 30s at worst. My guess is low 40s for your profile. I welcome disagreements with explanations and these are just my educated guesses after driving my 2010 for 42,000 miles. Remember, YMMV.

 

My commute to work is 6 miles each way. Doing this and running around town I get about 43MPG on the average vs 52-55 if I am on a long freeway drive. However, if you are in a colder area, it could drop a little more as the car will take longer to warm up.

 

This morning at 46 F weather, my gage was reading 55.2 MPG and I set out on a 3 mile trip to gym (170 miles on tripmeter). It went down to 54.6, but after 2 mile , it held that figure and even went up to 54.7. These actual MPG numbers would be in the 52.x range (actual is about 4 or 5% lower than indicated).

Couple weeks ago, I was at about 52.3 MPGs and got into a slew of 2 mile one-way trips to the hardware store, 4 minutes driving. After maybe a dozen trips, it finally dropped under 50 on the gage and settled about 49.5 when I gas up. The actual when filling up was about 46.8 MPG.

There is a gage called Hybrid System Indicator and I highly recommend you keep an eye on that. There is a DVD when you buy the car that expalins how to use the gage. Owners manual explains too.

A $9 tire pressure gage and $50 one gallon air compressor will make keeping tires inflated easy. I have them at 38 psi front and 36 psi rear, check when cold.

These are fabulous, quiet, comfortable and nice driving cars. I say buy one.

 

A lot of good information in the above posts; perhaps too much for some readers. Here is the condensed version:

Short trips hurt mileage in all engine powered cars, hybrid or normal. You will still get better mileage from a Prius.

Tom

 

When you test drive a Prius, if possible, have them see that the tires are nicely inflated. They could easily be under 30 psi, and you'd never know it looking.

A the beginning of your test drive, click the TRIP button on steering wheel to trip A or B, hold the button and reset the tripmeter.

Hit the DISP botton next to trip button until you see the 'Hybrid System Indicator' gage. Glance here and there (not too much) when accelerating to keep the bar out of the PWR zone when able. Prius gives decent acceleration even keeping bar out of PWR zone, but sometimes must give more gas.

As you start out the average will be all over the place. It will take several minutes for it to get in the 30s, few more to get into the 40s.

On my test drive, pretty sure we were out for 25 minutes, and when we pulled back into the lot, it was reading 51 MPG (warm at 70F). This was suburban, little highway, lots of streets driving.

Take you time and enjoy the car. Give a couple solid 20 minute test drives. It's like nothing you've ever driven before!

Good luck!

 

Cindy, don't worry. With 10 mile and 6 mile round round trips you definitely can be in the 40s range, easily. Your temperatures are lower than ours and you likely will need the heater running. 30's, 20's, forget it. Won't happen.

 

You are a perfect candidate for the Plug-in-Prius if you can wait several months with your purchase.

 

Instead of the air compressor, $10-20 for a floor style bicycle pump works just fine for many of us.

 

You'll be fine, especially assuming you're not turning off the car at your daughter's school (i.e. stop, let her out, then escape from the hordes of other parents there too). 10 miles is a pretty good trip. If you're concerned about other short trips, try to chain them together; the first stop should be the furthest away, or maybe the one where the car will be off for the shortest period of time. Then hit other errands along the way back home, and the car will either stay warmed up the whole time, or at least will be closer to warmed up. This also has the advantage of you driving fewer miles than making separate trips, which is an even easier way to save fuel than by buying an efficient car...

 

When you start out your 3 mile trip, the gas engine will come on, but once you go a 1/4 mile or 1/2 and stop at your first light (if you have one), the engine should shut off the whole time you're stopped. ding, points for Prius. As you accelerate off on battery to about 10 MPH, the gas engine will join in, but soon as you take your foot of the gas pedal to slow, gas flow will stop again. ding, more points for Prius. Sometimes you'll score EV driving up to 20, 30, even 40 MPH for a short while, ding more points.

There is no non-hybrid car that can touch the Prius even for short trips on fuel economy. The car works very efficiently to minimize use of gas. 10 and 6 mile round trips will land a subcompact Honda Fit, for example, in the very low 30s on MPGs.

I don't drive all that far myself, 50 mile round is rare, and lowest on gage is about 49.5 last tank. Corrected that by starting to use HSI gage. I want my fuelly average over 50.

 

Just a thought ... go to the site Fuelly | Share and Compare Your MPG
Even a subcompact Honda Fit is about 33 overall compared to 2011 Prius at almost 48 MPG.