Getting 62 MPG in my revived 2003 Prius

[orange4boy]

A few aero mods, a bit of learning and little help from my friends.

62 mpg 420 miles, 6.77 gallons and $25. That's 3.8 L/100Km for my fellow Canadians.

Thanks to all the helpful Prius chatters. You know who you are.

[Tideland Prius]

wow! That's Gen 2/3 territory. Congrats!

[orange4boy]

That's with 2 passengers, 1 22lb Jack Russel, 2 60lb deep cycle batteries and misc. luggage.

This is how I manage it:

Techniques:

P&G when below 64 KPH
Keeping to 55 mph and below without inducing major road rage. "Only in Canada you say? Pity"
Timing lights and avoiding the brakes
Maximizing momentum
Safe drafting when possible
Engaging regen with brake pulse then backing off. Seems to reduce friction brake losses.
Shift to neutral at lights. Saves ~1 amp.

Current Mods:

Basjoosed hood and headlights with closed cell foam tape.
Grille block. Internal, upper and lower.
Engine bay / hood insulation.
Type WS transaxle oil (to replace type IV)
Windshield rain deflectors removed (front windshield was replaced without rain gutters)
Low profile wipers
Custom stainless 18" screw on mooneyes
Front air dam
4" Side kilts
Traction battery pre-heater
Front air dam
5-20 synthetic.
Nokian WRg2 52 psi front, 50 psi rear.
12V system run with deep cycle batteries
750 watt transaxle block circulation tank heater
1500 watt engine block circulation tank heater. 70 - 90˚C Operating temp at start.

Planned Mods:

Regen boost circuit (autospeed article)
Rear stainless wheel skirts
Rear wheel boattails
Belly pan upgrades
Optimize front air dam transition
Active grille block using electric antenna hack.
Rear fastback conversion with plexi
Basjoos door gaps with foam tape

[Tideland Prius]

holy cow that's a lot of mods.


I ran 38/36 on Integritys on the 2005 Prius and got a 3.9L/100km tank. Shows you the advances of the Gen 2 over the Gen 1! I can't wait to see what you'd get on a Gen 2 or 3 (3.5? 3.0?)

[bwilson4web]

Excellent list:

Originally Posted by orange4boy

. . .

Techniques:
P&G when below 64 KPH
Keeping to 55 mph and below without inducing major road rage. "Only in Canada you say? Pity"
Timing lights and avoiding the brakes
Maximizing momentum
Safe drafting when possible
Engaging regen with brake pulse then backing off. Seems to reduce friction brake losses.
Shift to neutral at lights. Saves ~1 amp.

That is "~1 amp" of traction battery current or aux battery?

I've been looking at a little simpler system based upon the accelerator automatically shifting into "N" when released and back into "D," if already in accelerator "N," for brake. Alternatively, shift to "B" to soften traction battery charging. This needs study and of course, careful testing. One thing that pops out is a smarter cruise control: (1) slacks off up grade, and (2) speeds under 23 mph (37 kph.)

Other than Yankees tourists, is it possible to piss-off a Canadian?

Originally Posted by orange4boy

. . .
Current Mods:

Basjoosed hood and headlights with closed cell foam tape.
Grille block. Internal, upper and lower.
Engine bay / hood insulation.
Type WS transaxle oil (to replace type IV)
Windshield rain deflectors removed (front windshield was replaced without rain gutters)
Low profile wipers
Custom stainless 18" screw on mooneyes
Front air dam
4" Side kilts
Traction battery pre-heater
Front air dam
5-20 synthetic.
Nokian WRg2 65 psi front, 50 psi rear.
12V system run with deep cycle batteries
750 watt transaxle block circulation tank heater
1500 watt engine block circulation tank heater. 70 - 90˚C Operating temp at start.

Impressive tires!

Normal USA circuits are 15 A @120 VAC ~= 1800 W. Do you have a single, 20/30 A service plug? Or are these 220 V. heaters?

Do you have a warm-up protocol ... say 1-4 hours before driving?

I've been following your progress from transaxle replacement and many of the other changes. This journey would make an excellent web page, a 'how to do it.' <GRINS> So you got the car back in September and this is after 6-7 months?

BTW, I wouldn't worry too much about going with an NHW20, not that they didn't do some good stuff and it is a larger vehicle with more space. A lot of that can be mitigated by simply removing the rear seat back and not bolting it back in. This would let you put in oversized loads.

All in all, an excellent effort.

Bob Wilson

[orange4boy]

That is "~1 amp" of traction battery current or aux battery?

One amp from the traction battery as read by the Graham scanner.

Normal USA circuits are 15 A @120 VAC ~= 1800 W. Do you have a single, 20/30 A service plug? Or are these 220 V. heaters?

I get away with one 15A outlet. One plug for the 1500W the other for the 750W tank and the 200W battery warmer. I think they must pull a bit less than their ratings.

[quote]Do you have a warm-up protocol ... say 1-4 hours before driving?

I have timers that switch on all the heaters about 1- 1.5 hours before driving. Since my engine compartment is so well sealed and insulated, It does not take long. I tested the 1500 watt ICE heater and it got the engine from 10˚C to 70˚C in 45 minutes. This fast heat means less wasted energy from convection losses.

I've been following your progress from transaxle replacement and many of the other changes. This journey would make an excellent web page, a 'how to do it.' <GRINS> So you got the car back in September and this is after 6-7 months?

I might do a web page in the future but right now I just don't have the spare time. I do have lots of pictures of the progress though.

BTW, I wouldn't worry too much about going with an NHW20, not that they didn't do some good stuff and it is a larger vehicle with more space. A lot of that can be mitigated by simply removing the rear seat back and not bolting it back in. This would let you put in oversized loads.

I think I like the challenge of the NHW11 better. There is more low hanging fruit for the picking.

All in all, an excellent effort.

Thanks. I have to give you a whole bunch of credit, Bob. The mini scanner and your help made much of the Prius specific stuff possible.

Ecomodder was an excellent resource for the aero mods.

The best aero mods are yet to come...

[adric22]

I bet with the addition of an Enginer plug-in kit you could reach or exceed 100 mpg.

[orange4boy]

Originally Posted by adric22

I bet with the addition of an Enginer plug-in kit you could reach or exceed 100 mpg.

It's on the list. Perhaps this fall. I will probably go with lead acid though. I'm not liking what I'm seeing with their BMS and the failure rate of the lithium cells. I can always upgrade later as well. Plus I already have a set of lead acid cells here for my other EVs.

Fun fun fun.

[adric22]

Well, I have the Enginer kit in mine 2002 model. I only spent $1,500 on the kit and I average 74 mpg city/highway. I haven't had any trouble with the BMS but I also check on the charging periodically and if the balancers are beeping, I unplug it.

[vegasjetskier]

Originally Posted by orange4boy

Nokian WRg2 65 psi front, 50 psi rear.

What's the max sidewall pressure on those tires?