MPG for first 5 min of trip?

freedog · 12-13-2007, 08:37 AM

The bar graph for the first 5 minutes of any trip I make shows bad MPG - between 20 and 25, even though I get around 50 or better after that.
(Im in Florida where the weather has been perfect (high today is 80) so its not that the heater or a/c is working to control the climate of a frozen or hot interior.)

Is this normal?

qbee42 · 12-13-2007, 08:43 AM

Normal. All cars burn a lot of fuel warming up the engine and catalytic converter, and the Prius is no exception. That's the main reason short trips are so hard on mileage.

Tom

**efusco** · 12-13-2007, 11:07 AM

Whenever possible avoid briskly accelerating during the first few minutes....if you hear the ICE racing more than it usually does when warmed up you're getting lousy gas mileage. Look in the Knowledge Base forum for the 5 stages of hybrid operation article...in S1 the ICE tries hard to throttle back to ~1250rpm while the emissions control systems and ICE warm up. If you can go really easy during S1 you'll notice a real bump in that first 5 min MPG.

For instance...last night it took a very long time for me to get through S1...about 2 full minutes...but traffic was light so I just piddled along until I was in S2 (I use CAN-View to monitor the ICE rpm) and then took off...my first 5 min bar, in 30 degree temps, was almost 60mpg.

Doc Willie · 12-13-2007, 02:55 PM

So, would I be better off letting the ICE come on during the first 1/4 mile (mostly downhill) of my commute than doing it in EV mode, and having the ICE come on when I hit the flat stretch (a bit of stop and go, and then I start my P&G)?

qbee42 · 12-13-2007, 03:36 PM

Quote:

Originally Posted by Doc Willie

So, would I be better off letting the ICE come on during the first 1/4 mile (mostly downhill) of my commute than doing it in EV mode, and having the ICE come on when I hit the flat stretch (a bit of stop and go, and then I start my P&G)?

Yes. EV mode is never a good idea, unless you are moving a short distance at low speed, such as around a parking lot, or under some very special circumstances where you know your battery is going to be heavily charged in an upcoming downhill.

Tom

drees · 12-13-2007, 04:23 PM

I've found that to get the best mileage when the engine is warming up, you need to reach 35+ mph and stay at a relatively constant speed without much stopping and starting. If you can do that, mileage will be 45mpg+. For example, if I hit all the green lights on the surface streets on the way to the freeway, I'll get 45mpg. If I get stuck at a couple lights, I get 25-30mpg.

Unfortunately, most commutes start at slow speeds with a bunch of starting and stopping so I typically get 25-30mpg the first 5 minutes.

**efusco** · 12-13-2007, 06:06 PM

Quote:

Originally Posted by qbee42

Yes. EV mode is never a good idea, unless you are moving a short distance at low speed, such as around a parking lot, or under some very special circumstances where you know your battery is going to be heavily charged in an upcoming downhill.

Tom

+1

freedog · 12-13-2007, 07:03 PM

Quote:

Originally Posted by qbee42

Yes. EV mode is never a good idea, unless you are moving a short distance at low speed, such as around a parking lot, or under some very special circumstances where you know your battery is going to be heavily charged in an upcoming downhill.

Tom

I assume you mean EV is never a good idea in the first 5 minutes?

freedog · 12-13-2007, 07:04 PM

Thanks for the replies, guys. This is great info. Im really loving PriusChat.

**efusco** · 12-13-2007, 07:10 PM

Quote:

Originally Posted by freedog

I assume you mean EV is never a good idea in the first 5 minutes?

Never is a tough word..but rarely is certainly a good choice. The slower and longer the drive that first 5 minutes (where you'd be tempted to use the EV button) the better it is to let the car get through S1 by going through its programmed warm-up.
No touchy the EV button.

12-13-2007, 08:37 AM	#1
freedog Prius Newbie Join Date: Dec 2007 Location: Florida Posts: 14 My Car: 2008 Prius Package: #2 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	MPG for first 5 min of trip? The bar graph for the first 5 minutes of any trip I make shows bad MPG - between 20 and 25, even though I get around 50 or better after that. (Im in Florida where the weather has been perfect (high today is 80) so its not that the heater or a/c is working to control the climate of a frozen or hot interior.) Is this normal?

12-13-2007, 11:07 AM	#3
efusco Troll Slayer Join Date: Nov 2003 Location: Nixa, MO Posts: 14,703 My Car: 2004 Prius Package: #9 Nominated 1 Time in 1 Post TOTM Awards: 0 Friends: 26	Whenever possible avoid briskly accelerating during the first few minutes....if you hear the ICE racing more than it usually does when warmed up you're getting lousy gas mileage. Look in the Knowledge Base forum for the 5 stages of hybrid operation article...in S1 the ICE tries hard to throttle back to ~1250rpm while the emissions control systems and ICE warm up. If you can go really easy during S1 you'll notice a real bump in that first 5 min MPG. For instance...last night it took a very long time for me to get through S1...about 2 full minutes...but traffic was light so I just piddled along until I was in S2 (I use CAN-View to monitor the ICE rpm) and then took off...my first 5 min bar, in 30 degree temps, was almost 60mpg. __________________ Evan E. Fusco, MD Seaside 04BC9/OEM EVb/NAV & auto-BT/XM Radio, CAN-View, Shark Fin, BT Stiff. Plate, Skid Plate & Strut Support

12-13-2007, 08:43 AM	#2
qbee42 Senior Member Join Date: Mar 2006 Location: Northern Michigan Posts: 6,208 My Car: 2006 Prius Package: #7 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 6	Normal. All cars burn a lot of fuel warming up the engine and catalytic converter, and the Prius is no exception. That's the main reason short trips are so hard on mileage. Tom

12-13-2007, 02:55 PM	#4
Doc Willie Shuttlecraft Commander Join Date: Jun 2007 Location: Out there, somewhere Posts: 1,189 My Car: 2007 Prius Package: #5 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 9	So, would I be better off letting the ICE come on during the first 1/4 mile (mostly downhill) of my commute than doing it in EV mode, and having the ICE come on when I hit the flat stretch (a bit of stop and go, and then I start my P&G)?

12-13-2007, 04:23 PM	#6
drees Senior Member Join Date: Oct 2007 Location: San Diego, CA Posts: 384 My Car: 2008 Prius Package: #2 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	I've found that to get the best mileage when the engine is warming up, you need to reach 35+ mph and stay at a relatively constant speed without much stopping and starting. If you can do that, mileage will be 45mpg+. For example, if I hit all the green lights on the surface streets on the way to the freeway, I'll get 45mpg. If I get stuck at a couple lights, I get 25-30mpg. Unfortunately, most commutes start at slow speeds with a bunch of starting and stopping so I typically get 25-30mpg the first 5 minutes.

12-13-2007, 07:04 PM	#9
freedog Prius Newbie Join Date: Dec 2007 Location: Florida Posts: 14 My Car: 2008 Prius Package: #2 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	Thanks for the replies, guys. This is great info. Im really loving PriusChat.