What all devices in prius will affect gas mileage?

poodlemaster · 01-09-2007, 05:11 PM

i love my new 07 prius, and my wife and i are driving very conservatively to get the best gas mileage, but what electronic devices will actually affect the gas mileage?

1. radio
2. heater
3. a/c
4. headlights
5. wipers
6. or anything else i may have missed

thanks for the help. i'm a little new to the whole hybrid process.

qbee42 · 01-09-2007, 05:18 PM

Mileage is a matter of power consumption; only devices that consume large amounts of energy have a significant impact. On your list, the A/C and heater are the main culprits, although in the case of the heater it's not the electrical load so much as the fuel being burned to make heat.

Tom

ScottY · 01-09-2007, 05:25 PM

I think the top MPG killers are the heater, a/c, and headlights.

When you demand heat, the engine needs to run and consume fuel.

While the a/c is electric, it still consumes fair amount of power (I've seen current drain up to 10Amps in the summer).

The headlights use around 2 Amps. While not a lot, when you are sitting in traffic, they can drain the HV battery down faster.

Others on your list are negligible, IMHO.

Charles Suitt · 01-09-2007, 05:59 PM

<_< All devices will have some effect on fuel consumption. I agree that the heater has more than most others since it causes the ICE to run more. Whatever runs on electricity will cause the battery to be recharged and there's efficiency loss through the systems generating electricity. The halogen headlights actually consume about 60 watts and the HID headlights 35 watts [Page 419 in my 2007 Owner's Manual]. I agree that heating and air conditioning probably have the most effect. Some Prius drivers "warm up" the Prius before driving away - that would be a MAJOR reduction of fuel efficiency. With the ICE coolant thermos, the Prius warms up in a reasonable time. Another waster or fuel would be underinflated tires increasing rolling resistance. Some Prius drivers run Goodyear Integritoes at 44psi front/42psi rear to help a bit on MPGs - you can gain MPGs at the expense of a 'harder' ride. On my 2004, I ran at 40/38 psi, but on the new 2007 Touring, I run at 37/35 psi - too soon to evaluate fuel economy on the 2007, only ~1,600 miles on the clock.

The only source of energy in the Prius is gasoline, the Prius just uses it much more efficiently than conventional cars.

ENJOY YOUR PRIUS... it is, indeed, a remarkable example of superior engineering.

**Tideland Prius** · 01-09-2007, 06:12 PM

<div class='quotetop'>QUOTE(poodlemaster @ Jan 9 2007, 02:11 PM) [snapback]373302[/snapback]</div>

Quote:

i love my new 07 prius, and my wife and i are driving very conservatively to get the best gas mileage, but what electronic devices will actually affect the gas mileage?

1. radio
2. heater
3. a/c
4. headlights
5. wipers
6. or anything else i may have missed

thanks for the help. i'm a little new to the whole hybrid process.
[/b]

2, 3 and 6

6 = rear defroster. It draws more amps than any of the exterior lights or even the front defroster.

ScottY · 01-09-2007, 06:19 PM

<div class='quotetop'>QUOTE(Tideland Prius @ Jan 9 2007, 06:12 PM) [snapback]373327[/snapback]</div>

Quote:

2, 3 and 6

6 = rear defroster. It draws more amps than any of the exterior lights or even the front defroster.
[/b]

ohhh yes... I forgot about that. Thanks for pointing that out.

poodlemaster · 01-09-2007, 07:27 PM

The halogen headlights actually consume about 60 watts and the HID headlights 35 watts [Page 419 in my 2007 Owner's Manual].
[/quote]
i was under the impression that HID headlights use up more electric because it takes up more electric to ignite the xenon gas in the HID headlights. is that correct?

Pinto Girl · 01-09-2007, 08:13 PM

<div class='quotetop'>QUOTE(poodlemaster @ Jan 9 2007, 07:27 PM) [snapback]373352[/snapback]</div>

Quote:

The halogen headlights actually consume about 60 watts and the HID headlights 35 watts [Page 419 in my 2007 Owner's Manual].

i was under the impression that HID headlights use up more electric because it takes up more electric to ignite the xenon gas in the HID headlights. is that correct?
[/b]

I think it takes higher *voltage*...which is not really a measure of 'quantity,' but more of 'pressure' (if you think of an electrical wire like a water pipe).

**Tideland Prius** · 01-09-2007, 08:25 PM

<div class='quotetop'>QUOTE(poodlemaster @ Jan 9 2007, 04:27 PM) [snapback]373352[/snapback]</div>

Quote:

The halogen headlights actually consume about 60 watts and the HID headlights 35 watts [Page 419 in my 2007 Owner's Manual].

i was under the impression that HID headlights use up more electric because it takes up more electric to ignite the xenon gas in the HID headlights. is that correct?
[/b]

The low beams are 55W. The high beams are 60W.

HIDs need 20,000V (give or take depending on manufacturer) to ignite. I believe, that's what the ballast is for.

c4 · 01-10-2007, 10:23 AM

HIDs need a very high voltage with a bit of current behind it to *start* the arc, but that's only for a fraction of a second. Once the gas in the bulb is ionized, it forms a very low resistance path, and will stay ionized with very little power. Conventional fluorescent tubes work on a somewhat similar principle (ionized gas), and this is part of the reason why they are so energy efficient..

01-09-2007, 05:59 PM	#4
Charles Suitt Senior Member Join Date: Oct 2004 Location: Dallas TX Posts: 1,624 My Car: 2007 Prius Model: Package: #6 Touring Thanks: 0 Thanked 1 Time in 1 Post Friends: 0	<_< All devices will have some effect on fuel consumption. I agree that the heater has more than most others since it causes the ICE to run more. Whatever runs on electricity will cause the battery to be recharged and there's efficiency loss through the systems generating electricity. The halogen headlights actually consume about 60 watts and the HID headlights 35 watts [Page 419 in my 2007 Owner's Manual]. I agree that heating and air conditioning probably have the most effect. Some Prius drivers "warm up" the Prius before driving away - that would be a MAJOR reduction of fuel efficiency. With the ICE coolant thermos, the Prius warms up in a reasonable time. Another waster or fuel would be underinflated tires increasing rolling resistance. Some Prius drivers run Goodyear Integritoes at 44psi front/42psi rear to help a bit on MPGs - you can gain MPGs at the expense of a 'harder' ride. On my 2004, I ran at 40/38 psi, but on the new 2007 Touring, I run at 37/35 psi - too soon to evaluate fuel economy on the 2007, only ~1,600 miles on the clock. The only source of energy in the Prius is gasoline, the Prius just uses it much more efficiently than conventional cars. ENJOY YOUR PRIUS... it is, indeed, a remarkable example of superior engineering. __________________ Charles Suitt Dallas Texas 2007 Touring Edition (Former Prius: 2004)

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
How does the EV mod affect your mileage?	stomsf	Gen II Prius Fuel Economy	21	09-04-2008 02:19 PM
Headlights affect on fuel mileage?	likesmpg	Gen II Prius Fuel Economy	24	08-25-2007 05:04 PM
Did reprogram affect your mileage?	Azor	Gen II Prius Main Forum	47	03-06-2006 10:12 PM
Ever Wonder how an aero change will affect your mileage?	Tempus	Gen II Prius Modifications	1	06-21-2004 07:23 PM
Do option packages affect mileage?	aarons12	Gen II Prius Fuel Economy	5	06-21-2004 12:03 AM

01-09-2007, 05:11 PM	#1
poodlemaster Member Join Date: Jan 2007 Posts: 42 My Car: Model: Package: Thanks: 0 Thanked 1 Time in 1 Post Friends: 0	i love my new 07 prius, and my wife and i are driving very conservatively to get the best gas mileage, but what electronic devices will actually affect the gas mileage? 1. radio 2. heater 3. a/c 4. headlights 5. wipers 6. or anything else i may have missed thanks for the help. i'm a little new to the whole hybrid process.

01-09-2007, 05:18 PM	#2
qbee42 Senior Member Join Date: Mar 2006 Location: Northern Michigan Posts: 10,468 My Car: 2006 Prius Model: Package: #7 Thanks: 93 Thanked 387 Times in 289 Posts Friends: 10	Mileage is a matter of power consumption; only devices that consume large amounts of energy have a significant impact. On your list, the A/C and heater are the main culprits, although in the case of the heater it's not the electrical load so much as the fuel being burned to make heat. Tom

01-09-2007, 05:25 PM	#3
ScottY Senior Member Join Date: May 2005 Location: Long Island, NY Posts: 1,249 My Car: 2005 Prius Model: Package: #3 Thanks: 0 Thanked 2 Times in 2 Posts Friends: 1	I think the top MPG killers are the heater, a/c, and headlights. When you demand heat, the engine needs to run and consume fuel. While the a/c is electric, it still consumes fair amount of power (I've seen current drain up to 10Amps in the summer). The headlights use around 2 Amps. While not a lot, when you are sitting in traffic, they can drain the HV battery down faster. Others on your list are negligible, IMHO.

01-09-2007, 07:27 PM	#7
poodlemaster Member Join Date: Jan 2007 Posts: 42 My Car: Model: Package: Thanks: 0 Thanked 1 Time in 1 Post Friends: 0	The halogen headlights actually consume about 60 watts and the HID headlights 35 watts [Page 419 in my 2007 Owner's Manual]. [/quote] i was under the impression that HID headlights use up more electric because it takes up more electric to ignite the xenon gas in the HID headlights. is that correct?

01-10-2007, 10:23 AM	#10
c4 Senior Member Join Date: Mar 2005 Posts: 524 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	HIDs need a very high voltage with a bit of current behind it to start the arc, but that's only for a fraction of a second. Once the gas in the bulb is ionized, it forms a very low resistance path, and will stay ionized with very little power. Conventional fluorescent tubes work on a somewhat similar principle (ionized gas), and this is part of the reason why they are so energy efficient..