Edmunds.com | Inside Line | Auto Observer Your Account | Help | Directory
You are here:
![[F]](http://a332.g.akamai.net/f/332/936/12h/www.edmunds.com/media/townhall/webxicons/site.gif){kind=small}
Forums
Hybrid Vehicles Toyota Prius Toyota Prius MPG-Real World Numbers
767 messages, Last post on Sep 28, 2009 at 9:21 AM
You are in the Toyota Prius Forum. Your Host is pf_flyer
I have a 08 prius and was getting 48.6 MPG now that it has gotten cold the MPG has drpopped to 42. I drive about 8 miles to work each day. The tem is in low 30's and high 20's. Is this common. 
|
|
|
Replying to: oldcoach (Nov 20, 2008 10:35 am) 
|
|
|
Replying to: pf_flyer (Nov 19, 2008 6:02 pm) |
|
|
Replying to: oldcoach (Nov 20, 2008 10:35 am) Here is a post I made here 2 yrs ago on the Camry Hybrid forum. It applies to the Prius obviously but it also applies to all vehicles equally... quote: Now that winter is fully here you might want to take into consideration some of the following factors which can often be outside your control entirely. These generally act to decrease your fuel economy. But, hey, it's the same for every vehicle on the road as well. For some it's even worse. Factors affecting your FE ( and everyone else's also, btw ) in decending order of importance... 1) Towing anything is a huge penalty possibly as much as a 50% reduction in FE 2) Lots of weight in the vehicle, passengers cargo etc. ( EPA tests are done empty ) deduct up to 20% from your 'Norm' 3) Short trips under 10 min - deduct 20% from your 'Norm' 4) Snow, Rain, sleet - deduct 15% 5) Strong head wind - deduct 10% 6) Cold weather - deduct 5 - 10% 7) High speed driving 0ver 70 mph - deduct 5 - 10% 8) Many starts from a dead stop ( going from stop sign to stop sign to stop sign ) - deduct 5 - 10% 9) Terrain - fortunately 'what goes up..' usually this balances out on a RT 10) Winter fuel - deduct 2 - 5% 11) Low tire pressure - ? How low Now these are cumulative, so short trips with a lot of stops ( -20% ) in winter ( -7% ) on slick pavement ( -15% ) can result in as much as a 40 - 50% loss from your personal 'Norm'. The bright side of this is that your 'Norm' is higher than most others at 39 mpg ( 48 mpg Prius ). If your Norm was only 26 mpg for example you might expect to get 13-15 mpg. unquote |
|
|
I'm not so sure those items are absolutely cumulative though. In my expeience, the worst mileage drop I've ever recorded has been on the order of 15%, max. If I see anything worse than that I assume I'm looking at some extraordinary circumstance like being stuck in 5mph traffic for a couple of hours or I'm looking at some kind of issue with the car. I think I'd be hard pressed to come up with a situation where my mileage hit for an entire tank would ever get close to 20%, much less 40-50% In these days of "instantaneous mileage readouts" you could certainly be aware that when you're sitting at a traffic light idling that you're mileage is really low for that stretch of time. But as with everything else... you mileage may vary! 
|
|
|
Replying to: pf_flyer (Nov 24, 2008 11:15 am) As to them being additive ... consider what your fuel economy might be in winter, in icy conditions ( poor traction ), into a headwind, on a short trip of less then 10 min. I'm certain that a Prius would be no more than 30-35 mpg for that trip. A 30 mpg midsized sedan might be in the mid/high teens. if these were your driving conditions for an entire tank or for the entire winter...... The key variable is the length of the trip. It's immediately noticeable on the hybrids that have a data-capturing MFD. The first 5 min of any trip is death on fuel economy. It's this first 5 min segment that has to be overcome in order to improve the total fuel economy. The values noted are not additive to the maximum value in every case but it's possible to construct a 20% or 30% or 50% reduction in fuel economy based on outside influences. |
|
|
I've been in all those conditions, I've been in multiple combinations of those conditions. I'm not arguing that on a 10 minute trip that my mileage, if I bothered to measure it for THAT 10 minutes, is not going to be low. But I've NEVER been close to a 30-50% reduction in mileage at a fillup on any vehicle. And I don't think I'd get close to that kind of reduction driving a Prius either. The instantaneous stuff is interesting, but I'm not sure it really means anything. If I'm stuck on an icy road into a headwind for a 10 minute trip (say for example, driving the 5 miles home from my car dealer after a wintertime service) there's not a lot that I can do about that, nor do I expect that for that VERY small segment of my travels that I'm getting optimal mileage. The only vehicle I've ever driven extensively with a mileage readout was a Volvo V70 we had as a one week rental on a vacation in CA. After the initial fascination, I chenged the display so I couldn't see the mileage readout as there were far more important things to watch out for on the freeways of Southern California! 
|
|
|
Replying to: pf_flyer (Nov 24, 2008 11:54 am) Cold day, snowy, short distance, many stops, strong headwind (looks like an Alberta Clipper maybe!), full load of passengers, winter fuel, and maybe tires down a few pounds... then I am looking at around 90% lower fuel economy, or around 4 mpg.  Uh... no, I don't think so. It might be as much as 40% less than optimal, maybe 50% if in addition to the above I don't do anything to try to save fuel, such as anticipating stops and using a light foot on the gas. But nothing close to 90%. Unless maybe I were also towing a 3000 pound trailer up a mountain. That might do it. Until the FE drops to zero when the engine blows up.
|
|
|
Replying to: backy (Nov 24, 2008 1:00 pm) Here's two really simple examples. You're stuck in traffic in a snow storm not moving at all. Stay there too long and you'll run out of gas. Yes your fuel economy is ZERO! Anyone who's towed with a truck knows that towing someing will cut fuel economy roughly in half. In the Prius it is absolutely clear from the graphical MFD that if you drove an entire tank, or an entire month or all year making just 5 min trips from home to work and back that your fuel economy would be in the 25-35 mpg range at best instead of 48 as most drivers get. And the more bad factors that you add to the equation the works the worse is the total.
|
|
|
Replying to: kdhspyder (Nov 24, 2008 2:55 pm) I agree that if I sit with the engine running, FE is zero. But that isn't what we are talking about. Anyway, if all I used a car for was 5-minute trips to/from work, I'd look for something other than a Prius. A bike or moped, maybe.  Or a used compact that gets 25 mpg under even those conditions but cost a whole lot less than a Prius.
|
|
You are here:
Forums
Hybrid Vehicles Toyota Prius Toyota Prius MPG-Real World Numbers
New? Join Now!
Forum Tools
Search Forums
Browse by Vehicle
2010 Toyota Prius
Browse by Board
Browse by Topic
Today's Chats
