gas gauge down 4 bars after only 71 miles?!

Yeah, it'll still vary some, especially if you're only partially blocking the grill. But by the 2nd or 3rd bar of your Consumption screen (i.e. 5-10 minutes into the drive) and assuming you aren't tailgating people and racing to reach each red light and stop sign as quickly as possible, it should be a bit higher.

I can see how this sorta thing would be frustrating to experiment with if you don't have a way to actually check the engine temperatures, and if you don't have experience driving the Prius in warmer temperatures to make you aware of other things that could significantly hurt your MPG... Driving style wise, generally speaking, you want to try to maintain a constant speed as much as possible. Be very aware that every time you accelerate you're using energy and every time you brake, you're going to need energy to rebuild the speed you just lost.

That means keep a nice long stopping distance to use as a buffer so you don't have to match every slow-down the person in front of you makes, on 3+ lane roads stay in a middle lane to reduce the likelihood of having to slow down for someone who's making a turn, on 2 lane roads stay on the right as much as possible so you can go nice and slow and anyone who has a problem with it will pass you. Prius frequently gets it most amazing mileage in the 30-40 mph range, and in stop and go traffic when it can keep its combustion engine turned off for long periods of time you'll frequently see bars on the Consumption screen as high as the 70's and 80's.

Keep experimenting with it, my guess is still that it's just the temperatures hurting you. Blocking your grill can significantly mitigate the temperature issue but definitely doesn't fully solve it. If push comes to shove I'd probably be game to meet up so we can take a quick ride in your car with my scanner hooked up and see precisely where your temperatures are.

 

I get terribly resentful of tailgaters. I start muttering "**** you, I'm not going to spend my gas on speeding up for your sake, MEESTER GUY!" My friends laugh at me when it happens while they're in the car.

Possibly they laugh uncomfortably. I'm not quite sure.

If you're being tailgated while in the rightmost lane, I say just let go of the gas pedal and let Apple slow down until they pass you. Don't be surprised if they rev their engines loudly when they do... Some people seem to have some serious emotional issues when it comes to Prii. Though that seems to happen more frequently up here in the 'couve than down in Portland.

You'll hear talk about "feathering" the gas pedal in the hypermiling circles, which means pushing down on it very very lightly ("as light as a feather") to maintain a constant speed without accelerating. You probably want to watch the Energy screen rather than Consumption while trying to learn that technique -- the "ideal" amount of pressure should result in no arrows going in or out of the battery on the Energy screen. If there's arrows going into the battery, you need to push down a little harder. If they're going out of the battery, you need to lighten up.

HOWEVER, pulse and glide is really mostly relevant when you're on fairly clear roads with relatively little traffic and few red lights, stop signs, etc. In terrain like what you're describing you'd mostly have to sorta do "predictive driving" -- which simply means if there's a red light or stop sign coming up, don't accelerate all the way up to the posted speed limit.. And if someone is tailgating you, maybe even pull over to let them pass and stay secure in the knowledge that with their driving habits, they're probably getting less than half the gas mileage you are.

That being said, for 10 minute drives in 30 degree temperatures, don't expect to get significantly higher than 25 mpg, regardless of the terrain or of your driving style. Under those conditions, your car is unlikely to have reached "normal" operating temps yet. I'd suggest taking Apple out for a 20-30 minute drive sometime just to verify that you don't have any other issues going on.

Here's a photo of my Consumption screen and a screenshot of my Torque screen at the end of a ~20 minute drive I took earlier today, when temperatures briefly hit 50F. You can see my coolant temp made it all the way up to 181.4F and while the first 5 minutes of my drive averaged around 30mpg, after that I made it into the 50-60mpg gauge and stayed there. When it's colder out, it takes 2-3 bars to get to that point.

 

Prof, bear in mind you are not going to effectively be able to P & G until you have reached stage 4 of the engine warm-up -- and after 10 min driving you'll only just be getting there. If you want to learn more about the 5 stages of Prius engine warm-up, click on the link (Hybrid Warm up) in my signature.

Hope that helps.

 

Another thing to bare in mind is that for a 10 minute drive, the actual difference in money spent between 25mpg and 50mpg isn't all that great.

Let's say you're covering 5 miles in those 10 minutes (which at least in my neighborhood is generous)...

5 miles / 25 mpg = 0.2 gallons
0.2 gallons * $3.00/gal = $0.60

5 miles / 50 mpg = 0.1 gallons
0.1 gallons * $3.00/gal = $0.30

So you're talking about a hypothetical savings of around 30 cents per 10 minute drive. Not something to get too terribly worked up over.

Where it really counts, on longer drives that take you out of town (or at least out of your neighborhood) you'll find your car will consistently hit those higher mpg numbers.

 

Do not confuse better MPG with using less gas, closer is cheaper!

 

Sounds like you might be happier with a Nissan Leaf.

 

Even after warmup, and even with the mild winter temps here in AZ, my experience has generally been that pulse and glide is not very helpful in winter. The problem is while you are gliding the engine has cold air blowing over it and you will quickly trigger another warm up cycle even once you've gotten over the first one. With temps in the 40s-60s here I can get around that with partial grill blocking, but I would imagine at colder temps this effect will be dominant even with grill blocking.

Short trips and cold weather will certainly cut into your mpgs, but there are things you can do to help. Getting the ICE warmed up quickly while wasting as little gas as possible is key. A scan gauge, grill block, and even a block heater can all help with that. I'm not a real expert due to our relatively warm climate here, but I know there are many threads and collective learning on this topic here on PC and that many of our friends even in the far north have been able to make substantial improvements . I believe some advocate letting the ICE warm up before you start driving as a way to get it through the cycle with as little waste as possible. At the very least I believe the idea is to keep the load on the ICE as light as possible while its still warming up. Again, not an expert but that's the gist as I recall. Generally I think it comes down to the ICE running fairly inefficiently during the warmup cycle, so the more you ask of it in this mode the more fuel you are going to waste.

Once its warm you want to keep it warm, which may mean thinking differently about routes and driving style than in other seasons. In mild/hot seasons I generally chose surface streets and use pulse and glide, and momentum conservation techniques to keep the ICE off as much as possible and operating as efficiently as possible when its on. In the winter I usually find it better to just take the freeway and keep the ICE running the whole time but as efficiently as possible by keeping speed relatively constant and as low as safely feasible. In winter particularly it also helps if you can cluster short trips together to take advantage of the retained heat in the coolant thermos vs. going through a cold start for each trip.

Rob

 

A few more thoughts:

Bear in mind that the Gen 2 has a flexible bladder in the fuel tank that greatly complicates the job of the fuel gauge. This is sort of like a balloon that expands and contracts as the tank is filled and emptied to reduce the evaporative hydrocarbon emissions by minimizing the air/fuel contact area. Pretty cool really. However, the pliability of this bladder does vary with temperature and age, and that will interact with the fuel pump shutoff mechanism. The upshot is that "full" can be anything between <8 to >10 gallons. This adds to the uncertainty beyond that which still exists in the gen 3 fuel gauge.

My experience also is that the first pip is generally bigger than the rest on a good fill, which is probably where they take up some of the bladder slack in the calculation. It can easily be 100-150 miles. After that it tends to fall at ~40 miles per pip at ~50mpg. After that, the gauge tries to estimate what the total volume is and how much fuel is remaining as a percentage of the (variable) whole. So miles per pip can vary.

The safest thing is just fill up when it gets low, or use the trip meter and average mpg to estimate DTE based on how many gallons you know you put in last (not how many you think should be in the tank / bladder). Living in an urban area with a gas station (or 3) every mile I honestly just don't worry about it and fill up when it beeps / starts blinking. The only time I use the actual added gallons / expected average mpg thing is on a long drive across the desert.

Rob

 

the leaf is only 20k after tax credits, and is kind of second gen. a bit more than a 2007 prius, but a pretty great deal for what you get.

 

Squeeze them before you push them in. Don't worry the grills won't break.

 

My gas gauge acts crazy sometimes too. It seems like running almost all of the gas out, and then filling up helps mine.

 

Forget the indicators. Set the odometer to zero with a full tank, and then when you refill the tank, divide the number of miles driven by the number of gallons put into the tank. Repeat procedure at every fill-up.

 

Yup, there's something wrong with the pic, when people go for extended drives, just get good mpg with that warmed up engine, lol. Better strategy, win/win for people with sporadic driving needs, is to consolidate chores, as much as practical, do all your runs in one day.

Get good enough at that though, and your 12 volt starts getting neglected...

 

If I believed everything my indicator said, I got my best mileage ever during the winter. 3.8L/100km is what I got the other day on my commute, and it ties the record for the best number I got last summer on the same commute.