Less than 30MPG city driving! Why?

To be more clear, my point is that the car itself performs pretty much as advertised. As I said, I am a poor example because I admit to still be learning the best ways to drive a hybrid. As a quick cheat to my shortcomings, synthetic oil did give me quite a little boost in mpg.

 

I am sorry you were offended. I did not mean to be insulting. Yes, I did interpret your post to mean that you put the heat on during your short trips. Nonetheless, my point was my last sentence, that we all react to the weather differently based on what we are used to experiencing. This weekend it will be in the teens and twenties here, which will brutal for me, but I'm sure the man from Fairbanks who has been posting recently would be thrilled with those temps.

 

there is NO WAY....worth repeating... NO WAY, anyone can say what someone else should be getting for gas mileage.

simply because driving conditions like traffic, terrrain, temps, distance, etc etc etc, all play a part. and no one is in the same situation.

i meticulously track my mileage under all kinds of conditions, and have seen a 20 mpg difference in a route, with same temps, same distance, same route, same direction traveled.


well., 20 mpg difference covers the results of 90 % of you here. so what did change??

time of day... that's all.

actually repeated this measurement several times (easy to do since it used to be my daily commute) and although 20 mpg was the highest variation, i had 6 results that were over 18 mpg... those results were compared with 8 control trips i did... average trip mileage 56 mpg...high 61, low 54...

change time of day with resulting change in traffic density

averaged 41 mpg low 35, high 44 mpg

so that was difference in my gas mileage or another way to put it...whats the difference between 5 PM during the week and 5PM on the weekend?

so, i say that whatever you are getting in your Prius, its still gonna be 50-100% better than you got in your previous car. keep working the techniques knowing that for every mile you drive you are putting at least a nickel in your pocket

 

Amen.

 

Rexleeusa, do you ever use "B"? Or do you use "D" only?

 

I call you out on this Washington Dave! I can say with staunch certainty what gas mileage anybody on this board should be getting... provided that they drive an EV. The rest of you gas burners are on your own.

Oh wait... I had a point here. My point is that short trips in an EV have ZERO efficiency penalty. While the Prius might have five stages, EVs have ONE. The good one. So... even though I have a point, I guess it is still as OT as ever...

 

Trying cutting out Alton to Irvine to Bake. Go from Barranca to Bake. And on the way home, take Bake down to Barranca - that should help a little. I find Bake is pretty good heading south getting higher MPG's. Also - Try to avoid CC. I did the exact same thing when I got the Prius and used CC all the time. I didn't believe the posters here - but they are right. My mileage shot up on the same routes that I thought the CC was helping. If you really want to precise, do it it by tank. One tank of CC, and one tank of NO CC at all.

 

ok Darrell, i said gas mileage...

 

Why wait 20 seconds? Why don't you just go immediately? As for accelerating slowly, that might be your problem. See 2004 Toyota Prius FAQ. The late Dave Hermance is mentioned in there.

If you have zones where you should go ~30 to 42 mph, then (traffic and law permitting) you consider doing pulse and glide in those areas. Toyota.com : Hybrid Synergy View : 2005 : Fall : Prius Marathoners Top 100 mpg discusses the technique.

 

As the others mentioned, I would try these suggestions:

1. Don't bother letting the car sit 20 seconds before driving off. By that time, the engine has been sitting there idling and warming up for over 10 seconds and burning gas. It probably doesn't significantly affect mileage much, but at least you could save a tiny bit of time off your commute.

2. Don't worry about accelerating slowly. As long as the engine doesn't sound like it's racing too much, go ahead and use the gas pedal to get up to speed promptly. When the engine really sounds like it's racing is when fuel economy starts to suffer. Getting up to cruising speed quickly lets you spend more time with the engine either barely working or off (the MFD will indicate 50-99+ mpg) which will improve overall economy.

3. Trying to use CC on surface streets is often counter productive when you find yourself having to change speeds frequently. If you know you'll be going a constant speed for a while, then good, but otherwise you can be smoother with your feet.

You might try just driving the car without paying any attention to fuel economy (turn off the MFD), you might be surprised and economy goes up!

I have found certain types of city driving to be hard on fuel economy, particularly situations where you end up racing from stoplight to stoplight with little time to cruise.

 

Idle time is not negligible. During the 20 seconds (or is it 60?) that you sit motionless you get 0 MPG. Turn it on and drive it immediately, and your MPGs will go up. (And check your tires whenever the outdoor temp changes more than 20'F, or at least monthly regardless.)

 

The theory behind a small amount of idle time not significantly affecting mileage is this:

When the engine is warming up, the ECU keeps the car running primarily on battery (unless you push the accelerator down too far, then you'll hear the engine RPMs jump). Since while this is happening, you end up draining the battery more than usual, which the engine will have to charge up later, thus burning more fuel to recharge the battery later.

Some people have said that even going as far as waiting until the engine shuts off automatically can result in better fuel economy in extremely cold weather, but I can't find those posts at the moment.

 

The way I drive:
• As soon as the car is on I shift to D and drive away normally.
• Once the ICE is warm and the batteries at 80% charge I accelerate up to 40MPH.
• Then release the accelerator and press it again lightly until the ICE, Motor, and Generator lines are off in the Energy Monitor (Glide Mode).
• When the speed drops to 30MPH I accelerate to 40MPH and repeat.
• I glide when going down slopes or level roads.
• Use B only when going down hill to keep speed down to 42MPH (55MPH if very steep).
• On highways I cruise at 60MPH with CC.
• I always use the AC between 72 and 75 degrees F (it's hot in Puerto Rico).

My weekly average is 49MPG. My highway MPG is over 60. I drive an average of 50 miles/day. Environment is 85 degrees F in winter, 98 in summer, and 85% humidity. Road conditions are hilly, heavy traffic, and lots of pot holes. Sometimes I'm in a hurry and drive very aggressively, and yet I still get over 45MPH.

I'm happy with my prius. It has saved me over $400/month in fuel. I look forward in acquiring a plug-in or an all electric model when Toyota puts on sale.

But, if someone wants to give me a Tesla Roadster for my birthday I'll take it.

 

I typically average MPG around 55. I don't do anything special, I just drive like I normally drove in any other car. I accelerate at a prudent pace, I use CC on all highway's and longer lengths between stop lights, and I keep an eye on stop lights ahead of me and let the car glide in. Keep in mind that the more you try to drive on the Elec.Motor only the worse you will get, the battery is really only meant to assist to keep the ICE in the optimal range of efficiency. You can kind of think of the battery as being like the Leave a Penny / Take a Penny at the gas station. Its there so you don't have to break another bill, but it isn't intended for you to pay for your merchandise with either.
I live in Ohio and the past 5 days in a row our temps have mostly stayed around 10 degrees and I am still able to maintain a 43 MPG without an EBH and I still haven't put my grill block back in since before my christmas vacation trip cross country.

My Tips
1) Idle as little as possible, (this includes not warming up the car in the morning)
2) Only glide with no arrows (no energy going to or from battery) I only bother to do this rolling off the highway and the last 1/4 mile or so before stop lights.
3) Of course only ever use D, B is only intended really for coming out of a large mountain chain.
4) Obviously Tire pressure I typically go 44fr / 42r
5) Synthetic Oil / quality filter
6) Avoid driving with only Yellow Arrows on the MFD (exceptions parking lots, or in only very short bursts)
7) Light Loads (empty out junk lying around in the trunk)
8) If everything seems right try taking a look at the air filter (make sure it didn't suck something up)
9) Another tip is don't tailgate the car in front of you, Ideally you don't ever want to have to touch the brakes unless you are coming to a stop or making a turn if you by leaving an adequate distance between you and the car in front of you it will give you a buffer zone to adjust to their variance in maintaining their speed with only having to rarely touch the brakes.

 

Without some hard data to back it up that notion sounds unlikely. The engine RPMs audibly respond to changes in road speed and accelerator setting at all times, so clearly some fraction of the engine output is going to the drive wheels even during the warm-up period.

 

I'll assume you drive your car home at night (as apposed to having it hauled home), and, your portion of the daily commute that is uphill, those last 5 minutes, are downhill on the way home (I think my dad was the only one to walk to school "uphill both ways"). I'm real curious on what you get on that down hill portion. That ought to be pretty much total EV mode. That's got to up your average.

 

Like I said earlier, try blocking off the air intakes and watch your mpg's go up instantly, like the very next time you drive it in cold weather....still working for me....

 

While the car is in Stage 1 mode of operation, the engine RPMs do not change at all unless you give it more than 30% throttle or so, at which point the engine RPMs will jump up and you'll feel a surge of acceleration and you'll quickly know you've exceeded the threshold at which point the ECU has decided to start using the engine for forward motion. This is most noticeable if you have any sort of a hill to climb.

It doesn't take long to get out of S1 operation under normal temps, so if you're creeping around the neighborhood you may never have noticed it.

Start/stop driving when the engine is cold absolutely brings out the worst fuel economy in the Prius. Every single one of your driving patterns seems to fall under this except for your weekend trips so it's not surprising to me that your fuel economy is not meeting your expectations.

Even when the engine is warmed up, if you are doing typical city driving and are getting stuck at most stop lights, fuel economy will drop well below the EPA combined mileage numbers of 46 mpg.

In city driving, unless you can hit a decent number of lights and get some good cruising/coasting time in, mileage will suffer.

I very very frequently will see a 5-10 minute intervals in city driving where mileage is ~35mpg. With your city commute at speeds of 45-55 mph, unless you can hit green lights, you will be spending a lot of time accelerating and decelerating which is not good for economy.

So you've increased your fuel economy by 75% and still aren't satisfied?

Not all city driving is the same, as you have learned by now.

I have already suggested that you just drive the damn thing and forget about mileage. It will probably go up.

If you would like some further help, perhaps you can meet up with a local Prius owner, or perhaps you can take some short of a "typical" commute. Even just a picture of your MFD at the end of your commute would be helpful.