Mileage advice...

rebbi · 11-07-2006, 12:37 PM

Howdy,

Haven't posted in awhile. I've been too busy enjoying my new Prius ('06, Seaside, Pkg. 6). It's a honey.

My biggest challenge in squeezing out good mileage is that I normally do a lot of short hop driving; I live only a 3 minute drive from my office. Combining trips to warm up the ICE helps, but I know I could still be doing better. I have around 1700 miles on the car thus far.

Oddities: I actually seem to do better on the highway than in the city. Generally, I can cruise along at near 60 mph and still be getting around 55 mpg on the current stripe of the bar graph. Start and stop traffic on the streets seems to drag my mileage down. Stop and go highway traffic, where I can go for ten to fifteen minutes solely on the electric motor pushes average mpg way up...

After a couple of long road trips, I upped my tire pressure to the 42/40 readings recommended by some here (this is with the factory OEM tires). It initially SEEMED to me that my mileage actually went down when I did this, although that may have been because the change coincided with a return to more city driving.

Anyway, when I see people here post 70 mpg MFD screenshots, I'm amazed and don't know how y'all do it. Here are my tank averages so far for my first four fill-ups. Note that I didn't record the MFD average on the first two tanks:

45.97 mpg (actual, based on gallons filled)
43.60 mpg (actual, based on gallons filled)
47.35 mpg (actual, based on gallons filled) — 47.5 mpg on MFD
44.85 mpg (actual, based on gallons filled) — 48.9 mpg on MFD

Any reactions or advice from more experienced PC'ers much appreciated.

Thank you,

Steve

**Tideland Prius** · 11-07-2006, 01:03 PM

pretty good for what is supposed to be short trips.

If there's any chance you can do a cross town hop (errand or delivery), give it a shot and see how that affects mileage. You should be up into the 60s!

rebbi · 11-07-2006, 02:00 PM

<div class='quotetop'>QUOTE(Tideland Prius @ Nov 7 2006, 03:03 PM) [snapback]345086[/snapback]</div>

Quote:

pretty good for what is supposed to be short trips.

If there's any chance you can do a cross town hop (errand or delivery), give it a shot and see how that affects mileage. You should be up into the 60s!
[/b]

It really seems to depend on the traffic patterns and the route. There's one stretch of road that I often drive that I can do almost entirely in electric mode, and that bumps mileage up a bit, temporarily. What I want to know is how people here consistently break 50 mpg on a tank. I've not managed that, yet!

Thank you,

Steve

eagle33199 · 11-07-2006, 02:15 PM

With short hops (especially that 3 minute commute) you can't expect too much. That section you say you can do in all electric you might want to rethink - remember, all the electricity you use has to come from somewhere. Odds are you'll end up running the engine more/harder in order to regen that power.

As for the highway versus city - when you're warming up, highway will definitely be better. Having the engine running when at a stop runs down the mileage a lot, but on the highway you're moving rather fast with only a minimal increase in fuel consumption (over typical warm up and just sitting there).

Read up on the Pulse and Glide (P&G) techniques to help improve mileage where it's safe to do so - you accelerate to speed (using the gas engine), then glide down using no arrows (ie no gas or electricity being used), and repeat.

rebbi · 11-07-2006, 09:27 PM

<div class='quotetop'>QUOTE(eagle33199 @ Nov 7 2006, 04:15 PM) [snapback]345146[/snapback]</div>

Quote:

With short hops (especially that 3 minute commute) you can't expect too much. That section you say you can do in all electric you might want to rethink - remember, all the electricity you use has to come from somewhere. Odds are you'll end up running the engine more/harder in order to regen that power.

As for the highway versus city - when you're warming up, highway will definitely be better. Having the engine running when at a stop runs down the mileage a lot, but on the highway you're moving rather fast with only a minimal increase in fuel consumption (over typical warm up and just sitting there).

Read up on the Pulse and Glide (P&G) techniques to help improve mileage where it's safe to do so - you accelerate to speed (using the gas engine), then glide down using no arrows (ie no gas or electricity being used), and repeat.
[/b]

What you say about needing to regenerate the power from the gasoline engine is something I hadn't thought about. I sort of assumed I could get it back from braking, but I see your point.

As for Pulse and Glide, I haven't really tried that yet, but I'll read up on it as you suggest.

Thank you,

Steve

asills · 11-07-2006, 10:37 PM

I live in downtown Dallas and my 8minute trip out of downtown to the freeway gets me ridiculously low mileage. The first bar is about 12, the second bar is 25 if I'm lucky. The engine is cold during this period so that's the main reason for the super low rates.

If I just drive around downtown, with the engine warm, I still will only get 25 MPG at best. There are lights about every tenth of a mile and that is constantly forcing me to start from zero (always on unlevel streets, so I can't really use the electricity only), accelerate to about 20-25, then begin braking again for the next red light.

The only "city" driving where I get good mileage is suburb driving where there are long stretches of road without constant stop lights. Do a search on here, someone did a good writeup of how way the gas mileage ratings are set up.

If your experience is anything like mine, real city driving is TERRIBLE for mileage. When I'm lucky enough to get onto the freeway within a minute from start, my first bar is about 35-40 and the rest are 50+ (even 70+ at times). When I am in the city with lots of stop lights, I try and use the battery only whenever possible during acceleration (flat or downhill and very slow acceleration) and when that's not possible I try to get to my target speed or a bit over relatively quickly (I don't floor it but I don't take my sweet old time) then use the pulse and glide technique to keep the MPG as hight as possible for as long as possible.

rebbi · 11-07-2006, 11:00 PM

<div class='quotetop'>QUOTE(Adam Sills @ Nov 8 2006, 12:37 AM) [snapback]345260[/snapback]</div>

Quote:

I live in downtown Dallas and my 8minute trip out of downtown to the freeway gets me ridiculously low mileage. The first bar is about 12, the second bar is 25 if I'm lucky. The engine is cold during this period so that's the main reason for the super low rates.

If I just drive around downtown, with the engine warm, I still will only get 25 MPG at best. There are lights about every tenth of a mile and that is constantly forcing me to start from zero (always on unlevel streets, so I can't really use the electricity only), accelerate to about 20-25, then begin braking again for the next red light.

The only "city" driving where I get good mileage is suburb driving where there are long stretches of road without constant stop lights. Do a search on here, someone did a good writeup of how way the gas mileage ratings are set up.

If your experience is anything like mine, real city driving is TERRIBLE for mileage. When I'm lucky enough to get onto the freeway within a minute from start, my first bar is about 35-40 and the rest are 50+ (even 70+ at times). When I am in the city with lots of stop lights, I try and use the battery only whenever possible during acceleration (flat or downhill and very slow acceleration) and when that's not possible I try to get to my target speed or a bit over relatively quickly (I don't floor it but I don't take my sweet old time) then use the pulse and glide technique to keep the MPG as hight as possible for as long as possible.
[/b]

This is all very useful, Adam, and it also makes me feel a little better about how I'm doing.

I do think that your experience is similar to mine. Do you also find that when the engine is cold, it shudders when it shuts off at a full stop?

Thank you,

Steve

asills · 11-08-2006, 12:03 AM

<div class='quotetop'>QUOTE(rebbi @ Nov 7 2006, 11:00 PM) [snapback]345264[/snapback]</div>

Quote:

This is all very useful, Adam, and it also makes me feel a little better about how I'm doing.

I do think that your experience is similar to mine. Do you also find that when the engine is cold, it shudders when it shuts off at a full stop?
[/b]

Absolutely; when it kicks on too. Sometimes much more violently than I would expect. My wife was getting in the car once when the engine kicked on and the car lurched forward about 4 or 5 inches, making it a bit difficult to get into the car!

ken1784 · 11-08-2006, 01:08 AM

<div class='quotetop'>QUOTE(rebbi @ Nov 8 2006, 04:00 AM) [snapback]345136[/snapback]</div>

Quote:

It really seems to depend on the traffic patterns and the route. There's one stretch of road that I often drive that I can do almost entirely in electric mode, and that bumps mileage up a bit, temporarily.[/b]

It is not a good idea to be in electric mode too much.

Quote:

What I want to know is how people here consistently break 50 mpg on a tank. I've not managed that, yet!
[/b]

There is no chance to get 50 mpg on your 3 minute drive.

Please refer to your consumption screen when you finished the short trip.
You'll see something like picture below. It's from Japanese Prius shown as km/L.

10 km/L ~= 25 MPG
20 km/L ~= 50 MPG
30 km/L ~= 75 MPG
40 km/L ~= 100 MPG

If you finish the trip in 5 minutes, you'll see 25 MPG.
If you finish the trip in 10 minutes, you'll see about average 31 MPG.
I think you already know it is casued by warming up fuel use.

Ken@Japan

eagle33199 · 11-08-2006, 08:54 AM

to echo what ken said, don't use electric too much... unlike what Adam described, it's usually better to accelerate from a stop using the gas engine (as in the pulse and glide technique) than on electric - that type of acceleration will drain the battery very quickly, which is something you don't want.

And yeah, when the engine is cold the start and stops shudder quite a bit more than they do when it's warm (but it still does shudder when warm!)

11-07-2006, 12:37 PM	#1
rebbi Join Date: Jul 2005 Location: Austin, Texas Posts: 94 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Howdy, Haven't posted in awhile. I've been too busy enjoying my new Prius ('06, Seaside, Pkg. 6). It's a honey. My biggest challenge in squeezing out good mileage is that I normally do a lot of short hop driving; I live only a 3 minute drive from my office. Combining trips to warm up the ICE helps, but I know I could still be doing better. I have around 1700 miles on the car thus far. Oddities: I actually seem to do better on the highway than in the city. Generally, I can cruise along at near 60 mph and still be getting around 55 mpg on the current stripe of the bar graph. Start and stop traffic on the streets seems to drag my mileage down. Stop and go highway traffic, where I can go for ten to fifteen minutes solely on the electric motor pushes average mpg way up... After a couple of long road trips, I upped my tire pressure to the 42/40 readings recommended by some here (this is with the factory OEM tires). It initially SEEMED to me that my mileage actually went down when I did this, although that may have been because the change coincided with a return to more city driving. Anyway, when I see people here post 70 mpg MFD screenshots, I'm amazed and don't know how y'all do it. Here are my tank averages so far for my first four fill-ups. Note that I didn't record the MFD average on the first two tanks: 45.97 mpg (actual, based on gallons filled) 43.60 mpg (actual, based on gallons filled) 47.35 mpg (actual, based on gallons filled) — 47.5 mpg on MFD 44.85 mpg (actual, based on gallons filled) — 48.9 mpg on MFD Any reactions or advice from more experienced PC'ers much appreciated. Thank you, Steve __________________ "You are not required to complete the work, but neither are you free to abstain from it." Rabbi Tarfon, Pirkei Avot

11-07-2006, 02:15 PM	#4
eagle33199 Platinum Member Join Date: Mar 2006 Location: Minnesota Posts: 3,724 My Car: 2006 Prius Package: #7 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	With short hops (especially that 3 minute commute) you can't expect too much. That section you say you can do in all electric you might want to rethink - remember, all the electricity you use has to come from somewhere. Odds are you'll end up running the engine more/harder in order to regen that power. As for the highway versus city - when you're warming up, highway will definitely be better. Having the engine running when at a stop runs down the mileage a lot, but on the highway you're moving rather fast with only a minimal increase in fuel consumption (over typical warm up and just sitting there). Read up on the Pulse and Glide (P&G) techniques to help improve mileage where it's safe to do so - you accelerate to speed (using the gas engine), then glide down using no arrows (ie no gas or electricity being used), and repeat. __________________

11-07-2006, 10:37 PM	#6
asills Join Date: Jun 2006 Posts: 32 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I live in downtown Dallas and my 8minute trip out of downtown to the freeway gets me ridiculously low mileage. The first bar is about 12, the second bar is 25 if I'm lucky. The engine is cold during this period so that's the main reason for the super low rates. If I just drive around downtown, with the engine warm, I still will only get 25 MPG at best. There are lights about every tenth of a mile and that is constantly forcing me to start from zero (always on unlevel streets, so I can't really use the electricity only), accelerate to about 20-25, then begin braking again for the next red light. The only "city" driving where I get good mileage is suburb driving where there are long stretches of road without constant stop lights. Do a search on here, someone did a good writeup of how way the gas mileage ratings are set up. If your experience is anything like mine, real city driving is TERRIBLE for mileage. When I'm lucky enough to get onto the freeway within a minute from start, my first bar is about 35-40 and the rest are 50+ (even 70+ at times). When I am in the city with lots of stop lights, I try and use the battery only whenever possible during acceleration (flat or downhill and very slow acceleration) and when that's not possible I try to get to my target speed or a bit over relatively quickly (I don't floor it but I don't take my sweet old time) then use the pulse and glide technique to keep the MPG as hight as possible for as long as possible. __________________ What my MFD says I get: What my manual calculations say I get:

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11-07-2006, 01:03 PM	#2
Tideland Prius Super Moderator Join Date: Oct 2004 Location: Canada Posts: 14,192 My Car: 2005 Prius Package: B Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 12	pretty good for what is supposed to be short trips. If there's any chance you can do a cross town hop (errand or delivery), give it a shot and see how that affects mileage. You should be up into the 60s!

11-08-2006, 08:54 AM	#10
eagle33199 Platinum Member Join Date: Mar 2006 Location: Minnesota Posts: 3,724 My Car: 2006 Prius Package: #7 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	to echo what ken said, don't use electric too much... unlike what Adam described, it's usually better to accelerate from a stop using the gas engine (as in the pulse and glide technique) than on electric - that type of acceleration will drain the battery very quickly, which is something you don't want. And yeah, when the engine is cold the start and stops shudder quite a bit more than they do when it's warm (but it still does shudder when warm!)