37mpg City?

Sorry, you haven't done much to talk about your commute and w/these latest revelations, we don't even know if you're comparing apples to apples. Has your commute changed vs. when you were driving the Insight?

As for driving techniques, an example is Pulse and Glide plus Warp Stealth in the Prius II for maximum FE … - CleanMPG Forums. Are you using auto climate control or do you have the heat turned up above LO w/the fan running? The latter can cause the ICE to run (unnecessarily other than to produce heat for you) when it's cold esp. right after you've started thus hurting your mileage.

Of the previous car (02 Nissan Maxima) and another current car (04 350Z) where I've tracked mileage, I always fell well short of the (old method) EPA city mileage. The former was rated 20 city and the latter 19. The short drives and lots of idling killed mileage. It wasn't atypical to get 15-17 city on both. The only times I've exceed EPA mileage was on the Max w/long highway trips (28-29 mpg vs. EPA 26 mpg highway ratings).

Per Fuel Economy: Why You're Not Getting the MPG You Expect - MSN Autos "Shortfalls in mpg occurred in 90 percent of vehicles we tested and included most makes and models." when they compared their test results to the old EPa method.

 

Re: Rain, cooler temps.

Besides the questions others asked I may as well re-ask:
"Are you using auto climate control or do you have the heat turned up above LO w/the fan running? The latter can cause the ICE to run (unnecessarily other than to produce heat for you) when it's cold esp. right after you've started thus hurting your mileage."

 

Have you tried, like I suggested previously, just driving it normally? You said you were trying to force EV. That is not an efficient way to drive the car.

 

[repeat] Forcing the EV mode is a big mistake. It's not helping and it's probably hurting your mileage. Don't use it except for something like moving your car 35 feet in a parking lot.

Also, don't expect the engine to be completely warmed before 10 minutes. If you commute for only 20 minutes the first ten are aren't going to help your mileage.

Check your tire pressure. Try 42 front/40 psi back.[end repeat]

Since the OP didn't respond to my post there it is again. If he/she can't get into the mid 40s with a 25 minute+ commute then it's technique and other controllable parameters that are the cause. If the commute is ~10 minutes long then there isn't much he/she can do.

 

Re: Rain, cooler temps.

Heat on low. 47 mile round trip commute.

 

Re: Rain, cooler temps.

For the first few minutes, until the ICE is warmed up DON'T use auto and if you have the heat above LO, turn OFF the fan. If you're at a point where you have to go >42 mph, may as well turn it to auto/turn the fan on since the ICE has to run anway.

It's an interesting phenomenon to be at a stoplight w/a cold engine + heat on w/the ICE running. Right when you press Off, the ICE shuts down. Turn the fan back on: the ICE starts up....

I tried this same experiment on my mom's Altima Hybrid and it does the same thing.

 

Before you give up try some of the suggestions you got in this thread. From what I gather you already have your tires inflated higher; you're in California (assuming fairly warm part of it) which should yield higher MPG if you're easy on using A/C as you told us. The only thing I can see as additional opportunity is as others have suggested you're trying to hard by driving it too carefully. Before you approach a hill do you try to gain speed on the flat or downhill terrain? You need a good momentum so you spend less energy trying to make it up the hill (think of riding a bike).

If none of our ideas work find someone you know with another Prius (or rent one) and drive it on your route to see if there's any difference.

Good luck,

 

This statement tells me you haven't tried everything that's been suggested. You don't seem to be heeding what's been said about forced EV mode being inefficient. Furthermore, you aren't providing details about your drive for others to give you situation-specific advice.

Others are trying to help here. Seems to me the purpose of your post was not to solicit help but instead to complain. That's fine and that's your right, but state that up front so others don't waste time offering unwanted advice.

 

I concur with this.

 

Still waiting for this data, Rest...

BTW, I disagree that forcing EV mode in the manner you describe can not be less efficient. IMO, it can be. If you drain the battery enough before your next big hill to climb which also forces the engine to work harder than it normally would which puts it into an output range where the BSFC is higher, you'll consume more fuel.

Or you could prove it - and provide data on your fuel economy driving both methods. If it's your daily commute it won't take more than two weeks to accumulate enough data to determine if it's helping or hurting.

 

You drove a hybrid w/a totally different design and which AFAIK had no EV-mode.

 

Speeds? Lights and other stops? Traffic volume?

Oh, never mind. It seems you aren't really looking for advice and just want to vent. I'm out of here. :frusty:

 

Apart from the way one drives, the biggest impact with mpg is with those darn batteries having such a wide performance range. You can tell if you have a lower performance battery if the engine always kicks too soon in when moving away slowly from a stop. The one we own hardly ever uses battery only power, yet with a rental the engine rarely kicked in under 25 mph.

 

Just for fun, try never using the EV mode and pulse and glide a bit instead. For a couple tanks...

 

No, the test is the same for all light vehicles. See How Vehicles Are Tested and Fuel Economy Test Schedules. The new tests (included in MY 08+ ratings) are bracketed in red.

They don't measure the amount of fuel used, per the 1st URL:
"A hose is connected to the tailpipe to collect the engine exhaust.
The carbon in the exhaust is measured to calculate the amount of fuel burned during the test.
This is more accurate than using a fuel gauge."

I'm not sure how much the results on the dyno are adjusted for the MY 08+ method, but for the old method, per http://www.nhtsa.dot.gov/CARS/rules/CAFE/FuelEconUpdates/2003/index.htm: "The laboratory fuel economy results are adjusted downward to derive the estimates in the Fuel Economy Guide and on new passenger cars and light trucks labels. The city test value is lowered 10 percent and the highway test value is reduced 22 percent."

So given that the old test has very gentle acceleration and the Prius while running in EV mode emits no carbon, I'm not surprised the results are somewhat inflated.

BTW, you can find out what all vehicles, including the Prius got in the EPA tests at http://www.fueleconomy.gov/feg/epadata/08data.zip. It looks like the raw dyno # (for CAFE purposes) was 66.6 mpg city/64.8 mpg highway.