Is it Me or the Car?

One noticeable improvement you will definitely see is if you inflate the tires up to at least 40 psi.

 

Don't "glide" away from stops.
That's one of the classic blunders...
Instead, rapidly accelerate up to speed, then ease off. Not TOO rapidly (i.e., don't floor it), but do think about quickly getting up to speed. Very short accelerations, coupled with easing off and then gliding will improve your MPG.

 

I disagree. Moderate acceleration rate is acceptable, up to say 75% of the mid portion of the HSI, but anything more is counterproductive. It's Physics pure and simple and there are no "magic" portions of the engine power band that are much more efficient than any other, any more than there are certain speeds that will yield better fuel economy than others.
If you look at Bob's mileage graph, it's pretty straight.
I have found that if your really after mileage above all else accelerating very slowly will result in better mileage, but a more brisk rate of acceleration is a lot more acceptable to other traffic and doesn't hurt mileage very badly, unless the type of driving your doing requires constant decel and accels.

 

I agree with the faster acceleration. Before the 2010's and their HSI, someone had brilliantly come up with a rule-of-thumb for acceleration that works well: accelerate so you're getting 1/2 your MPH in MPG. So basically, you should have roughly 1/10 as many MPG pips as your current speed: 1 at 10, 2 at 20, etc. Also, there's always a point where you can ease off of your acceleration and still stay ahead, which for me is around 40 or so, I think.

This pretty much amounts to driving in the right 3/4 of the HSI. I really don't use the HSI anymore, since the MPG gauge pretty much tells you everything that the HSI can.

(I think the 1/2 MPH rule was perhaps for the pulse phase of P&G, but it works reasonably well for me for overall acceleration.)

Perhaps slower acceleration that this is the absolute, most efficient, but I think that most newbies make the mistake of accelerating way too slow, which annoys other drivers and really doesn't help on the mileage front.

HARD acceleration can kill your mileage, for sure, but moderate-strong acceleration coupled with looking ahead and driving smoothly is the key to sustained mileage and concentrating on embarrassingly slow take-offs is counter-productive.

 

There is good advise above, but you are a victim of the driving environment. Remember, the EPA conducts their test in am almost sterile environment, and tries to simulate real-world circumstances. The Prius is capable of much higher mileage ... but under the best of driving environments.

Next weekend fill the tank; press reset; drive out over to Annapolis. Cruise the back roads and drive between 45-55 mph. Drive as steady as possible, coasting on downhills; fill the tank again and calculate the mileage. I assure you your Prius will better the EPA figure.

It is a remarkable vehicle, and certainly capable of the performance promised. On the other hand, think of how much gas all the other motorist are using driving in that environment you decribe.

 

There are many factors that have a effect on MPG's. The BTU (energy content) of a gallon of gasoline. Gasoline with 10% Ethanol will have a 5-10% drop in BTU's which will effect your MPG's.

Short trips in cold weather will drop your MPG like a rock.

Road conditions, smooth paved level roads, will have a positive effect while wet roads will have a negative effect on mpg's.

Tires should be inflated, mine are at max sidewall pressure in all 4 at 44 PSI, Michelin Energy Saver tires.

The last and most important is driving habits. When my wife drives our car she will average 46-49 MPG. When I drive it is usually in the mid 50's.

Alfon

 

Based on experience, moving off briskly from a stop, even going into the Power zone for a few seconds, yields the better MPG overall. Also, learn to let up on the gas pedal and depress it again when moving, almost like you were shifting a manual transmission. This can cause the vehicle to shift modes and give you better efficiency. Use the MSI as a guide.

Try running in Power mode as well.

 

Completely normal.

 

Trip length is the biggest factor for me. Trips shorter than 6 miles or so drag my mileage way down. Trips over 10 miles get me over 50mpg easily when I'm on summer tires (mileage sucks on snow tires).

 

Not necessarily true for everybody. My commute during weekdays is short (about 5 miles) and I'm getting high 50's and it used to be low 60's before getting cold. Sometimes I have to drive to the city (20-35 miles) and my MPG gets a hit when that happens. So, the MPG mostly depends on traffic pattern and average speed, rather than distance of travel, unless it's like 1-2 miles, when there is no time for the car to even warm-up.

 

During the warm-up cycle, the car gets very poor mileage, compared to its normal running state. And the warm-up takes up to a couple miles, depending on the nature of the driving. So when I do 1-2 mile trips, the car is in the warm-up cycle almost the whole time and it is not uncommon for me to be under 30mpg for the trip. Of course, it takes some distance with a warm engine, getting well over 50mpg, before the consumption of the first couple of miles is averaged out. So while I commend you for getting high 50's on a 5 mile commute (excellent driving!), that definitely will not be the norm for most people.

 

Having read all of these comments (this thread and others) I have to believe some of it is based on car to car variation. EPA tests, which were revised in 2008, are not based on best case driving conditions but average city/highway driving conditions. No one should have to employ hypermiling techniques to get the window sticker estimate - either on a hybrid or a non-hybrid. I know of people who rented Gen II Priuses and drove them like they were mad at them over hundreds of miles and only managed to drag the mileage down to the low 40's.

 

I understand why cars get poor mileage in short trips, especially during cold months. My garage is not heated but it is well insulated and it rarely gets bellow 50, so that helps. But still, my car stays outside in the work lot and I still manage to get good FE (high 50s) even with my 5 mile trips (actually 4 miles because I usually go to the Gym after work, which is just 4 miles away). I find the warm-up period for the 2010 Prius to be really fast, but we haven't got much bellow freezing yet. 8 miles should be way more than enough to average it out, but that’s just based on my driving habits. I also spend part of the week in WI and the car is parked outside there, so I bet the warming-up time will be a lot more than I'm experiencing now after being overnight under -30F