poor mileage in town, better on highway

lol - 38 MPG is "lousy" city mileage... I have a friend who wants to sell you a large pickup truck that gets 8 MPG on a good day.

Tire destruction at 18k miles is indeed an indicator of something amiss. What kind of driving do you normally do in-town? Short trips, long trips, 30-mph streets, freeways, lots of stop-and-go, jack-rabbit starts...?

 

<div class='quotetop'>QUOTE(good dog @ May 31 2006, 09:18 PM) [snapback]263854[/snapback]</div>

My lifetime average is so far 45.8 mpg calculated and 46.5 mpg if I average what the trip computer says. This is a little better than I expected but I'm still working on improving it within reason (no overinflating tires to 40+ psi or driving 55 mph or trying to hypermile at 30-40 mph).

My commute is mostly highway at 67-75 mph.

Read http://www.fueleconomy.gov/feg/how_tested.shtml and http://www.fueleconomy.gov/feg/fe_test_schedules.shtml for how the EPA rating is derived.

Do you drive on the freweay at an average of 48 mph and a top speed of 60 mph? Did you know the EPA doesn't measure how much fuel is conumed by rather does it by this?
"A hose is connected to the tailpipe to collect the engine exhaust.

The amount of carbon in the exhaust is measured to calculate the amount of fuel used during the test.

This is more accurate than using a fuel gauge"

 

And in the city, do you drive less than 30 mph for 30 minutes at a time? Or do you do more like what my wife does, and drive 5 minutes or less with lots of accelerations up to 45 mph? The EPA city test mostly stays under 30 mph and contains far more lengthy times between stops than you would typically get in real city conditions. It's more like suburban driving at really low speeds.

The first 5 minutes or so of driving, while the engine warms up, typically gets between 25 mpg and 35 mpg. If your city driving trips are typically trips to the grocery store, school, soccer field, and local shopping centers, then the length of your trips are probably not much longer than 5 minutes or so. In such cases, the 25-35 mpg of the engine warm up period is going to dominate your average milage.

 

<div class='quotetop'>QUOTE(Marlin @ Jun 1 2006, 06:37 AM) [snapback]263952[/snapback]</div>

That's the truth, and life in this city! I'm getting ready to go to the bank then Safeway roundtrip about 4 miles, then the car will be parked the rest of the day, my wife will use the Muni and I'm working out of the house today, that will be our pattern through the summer.

I'm thinking about getting another Prius and only use it for trips over 15 minutes, LOL ... just kidding! But that Lexus Gs450h is pretty tempting ...

Hang in there 'good dog' some of the tips on this site have really helped, if nothing else my psyche, I don't feel like I suck as a prius driver anymore LOL. But with regard to lifetime average it will be hard to overcome two years of low mpg's. We changed tires at 23,000 and I rotated every oil change, well I asked the dealer too at least.

Oh yeah practical city tips in my newbie non-technical speak: overinflate tires I'm trying 42/40 for this tank, push up the hills use up the battery, recharge on the down slope and braking don't use "B", find routes with flats if possible to attempt the pulse & glide even if for only 1 mile, LOL, hey some practice is better than none!

I understand the concept of speed limits from the other threads, but this is a different world in the Bay Area if not CA in general, it truly is NOT SAFE to impede the flow of traffic, there are plenty of surface streets doing 55 mph . But I digress ...

b

 

<div class='quotetop'>QUOTE(good dog @ May 31 2006, 09:18 PM) [snapback]263854[/snapback]</div>

Your type of driving is exactly the reason Plug-in Hybrids will be very popular when they hit the market. Hopefully they will have a “no need to start gas engine this trip” button.

 

We live on a 10 mile curving mountain loop road with my wife's work and daughter school close to the bottom of the hill. It was a 4 1/2 mile downhill drive until a landslide closed the front side. Now with the 5 1/2 mile commute with part of it uphill we are down to 37 mpg.

 

<div class='quotetop'>QUOTE(Sufferin' Prius Envy @ Jun 1 2006, 12:59 PM) [snapback]264127[/snapback]</div>

Sign me up!

 

<div class='quotetop'>QUOTE(good dog @ Jun 1 2006, 12:18 AM) [snapback]263854[/snapback]</div>

Our experience exactly. No matter what we do, the first 5 minute bar will almost always register 25-27mpg, and a trip into town, the school, community garden, my wife's studio, the grocery store, Starbucks (hee hee), are all about 5 minutes from our house. The computer controlling the car seems to determine that the first 5 minutes is warm-up mode and thus runs less on the battery and charges battery more and possibly has a different air-fuel mixture. Some have said it is determined by engine temperature but our experience does not support that. It doesn't matter if we've been driving for an hour-if we turn off the car and come back and go again even in a minute or so, it will do the next 5 minute interval at 25-27mpg- I cringe now when I have to turn if on a short errand. I am learning to just not shut the car off if its a short stop and one of us can get out and to the task. Too bad it can't be locked it with the HSD on.

Highway cruising at say 65-70 we get 48-52 ish.

My wife is the principal driver and does a lot of these short runs, so the tank average is generally around 38-39 mpg though we routinely get 50-65mpg bars when we are driving more than 15 minutes or so. Still beats the ex-SUV that was getting 13.5 mpg average.

 

I also get better milage on the highway beacause it is much more consistent. I think because I live in South Florida and there is a light at every block, it is difficult to to use the pulse and glide.

For my first fill up i went 495 miles the computer read 46.7 mpg, but I calculated a bit higher on paper with 51.2. Not sure how that worked out since most other computers read slightly higher than actual average.

 

<div class='quotetop'>QUOTE(Prizzle @ Jun 1 2006, 05:48 PM) [snapback]264252[/snapback]</div>

Sure it can. Use the mechanical key to lock the door.

 

<div class='quotetop'>QUOTE(good dog @ Jun 1 2006, 10:55 AM) [snapback]264119[/snapback]</div>

The short trips of 5-10 minutes (assuming the engine is cold to start with) are a major contributor to bad mileage. What was your previous car's EPA mileage rating and what did you get compared to it over the same routes?

BTW, did you look at the EPA fuel economy driving cycle links I posted? Your drives are clearly a lot shorter than the EPA city cycle (31 minutes).

FWIW, here are some random car mileage figures that Consumer Reports found vs. EPA ratings (from the January 06 issue)
Pontiac Vibe - EPA: 30/36; CR: 19/36
PT Cruiser Limited (w/turbo charged 4) - EPA: 19/26; CR: 13/29
Chevy HHR w/2.4L 4 - EPA: 23/30; CR: 16/33

Gentle acceleration w/the ICE on may not be good for your mileage per http://www.geology.wisc.edu/~johnf/rechtin.html (I've read this article elsewhere before).

 

Here's (an excerpt of) an article that came from Consumer Reports about mileage shortfalls vs. the EPA rating along w/the best and worst performers.
http://autos.msn.com/advice/CRArt.aspx?contentid=4023460

 

Now we're cooking..been posting other threads., about the lack of attention to these problems..PHEV is the way out for the short trips and poorer gas ratings., and of course the ridiculous EPA rating.., that is a joke even with normal cars., much less Hybrids!

 

In the October 05 issue of Consumer Reports (where a full version of the article I mentioned came from), they also list the 10 vehicles where the city mileage is off the most. Here's 4 of them:

Jeep Liberty Diesel Ltd. 4WD: EPA 22, CR: 11, EPA shorfall: 50%
Honda Civic hybrid: 48, 26, 46%
Chrysler 300C: 17, 10, 41%
Chevy Trailblazer EXT LT 4WD: 15, 9, 40%

 

it's a game of averages. my daily commute is probably 10-15 minutes, stop and go, not nearly enough to get the average mpg for the trip up, i average around 42 - 45 mpg, sometimes it would be lower if my A/C is blasting and i'm sitting in traffic causing the ICE to start recharging the hybrid battery. but on longer trips on freeway (30-60mins at 60mpg) i'd average 50-55 which is sweet. after trying everything we know to help up the mpg (driving style), i've come to accept my city mpg, it's just the nature of my commute, unless if i take another route just to drive longer to get to work.

short trips kill mpg! (of any car)

 

<div class='quotetop'>QUOTE(cwerdna @ Jun 5 2006, 01:59 AM) [snapback]265876[/snapback]</div>

I know I shouldn't be surprised because we have the same shortfall with driving in SF, but I'm still surprised!

I guess it depends on how one describes city.

b

 

<div class='quotetop'>QUOTE(Marlin @ Jun 1 2006, 08:16 PM) [snapback]264350[/snapback]</div>

Oops. Bad case of SKS dependency. I'm going on the 12 step program right away.