The Premier's Limo: 2004 Toyota Prius "winter beater" ecomodding thread

[MetroMPG]

Air dam is a no go!

The butt dyno had me convinced it was good, but the numbers said otherwise (AAA-BBB coastdown runs).

Let this be a lesson! The butt dyno is a cruel mistress that will tell you what you want to hear, not what you need to hear.

Tail is a go!

After wasting many hours trying to get decent, repeatable MPG results from the Prius on Sunday (it's a tempermental, sensitive pain in the butt dyno), I finally came up with an approach that seems to work. So I did a bunch of A-B-A at 85 km/h (52ish MPH) and saw a ~7% improvement.

This was without any undertray at the car-to-tail transition and I discovered a potential problem there that was probably dragging the results down.

I'd like to test it again, with the undertray & at a higher speed -- thinking 105 kph (65 mph).

Will report back with more details...

[MetroMPG]

I put on a full width belly pan that extends from the middle of the car to the tail that covers most of the worst items under the car (gas tank, rear axle, most of the exhaust/muffler etc). It should help the tail perform better. I'll post pics this weekend.

It's pretty easy to add one to the Prius - there area many existing plastic panels & deflectors underneath to use as mounting points. I didn't have to drill a thing -- just used self tapping screws into plastic.

Sunday looks promising for testing weather again. Higher speed this time.

[MetroMPG]

Some more non-scientific numbers for the pile:

3.2 L/100 km or 73.5 mpg US on a trip I've done multiple times with the car.

(Previous high score was 3.3 ... yeah, yeah, I know it's within the range of measurement error.)

That's over 100 km (~60 mi.), with an 80 km/h (50 mph) cruising speed (mostly on cruise control, with some DWL on hills if no following traffic, no more than +/-10 km/h), mild & dry conditions.

It's the scenic country route that includes several stops, passes through 3 towns/hamlets, with easy (EOC/coasting friendly) sub/urban driving at either end.

I'll get pics of the belly pan... WHEN THE SNOW FRIGGIN' STOPS.

Also, schedule & weather didn't work out for the higher speed ABA testing I had hoped to do on the weekend. I will keep you posted on that.

[MetroMPG]

Well, I finally got the A-B-A testing done this week.

I repeated the tail test at 105 km/h (65 mph) with the new undertray-to-tail in place.

I also A-B'd the non-tail mods as a "package test" (wheel discs, rear skirts, grille block, mudflaps delete, passenger mirror delete, rear undertray).

It took 6 (SIX) hours. What a serious pain in the butt this car is for testing. So finicky.

But... decent results! I'll post them soon, but I make no promises it'll be posted today or this weekend. The first long weekend of the summer (May two-four, yay Queen Victoria!), so lots of play activities on tap.

Next up for the Limo:

Shoot some moving pictures for a video summary (meeting a friend with a drone copter possibly tomorrow). I'm thinking that YouTube will like a be-tailed Prius video. Iconic nerd car, reviled by traditional enthusiasts + ridiculous looking but effective aeromods = good sharing fodder. Bring on the haters!

Then de-mod and tidy up the car, do a couple of small repairs and sell it.

[MetroMPG]

I spent a couple of hours this weekend getting some moving pictures of the Limo from a quadcopter/drone setup.

A couple of my friends are in a local remote control aircraft club, and one of them has a bunch of drones & cameras. It's more complicated to do than I thought -- much time was spent for not a ton of footage.

Still, it was a learning experience (first time I've seen a drone in person), and some good shots were captured and will be edited into a YouTube vid at some point.

Also, with the arrival of good weather and more people outside, LOTS of people are coming up to me to ask about the car. It's fun. You wouldn't get more attention from a Ferrari.

[deejaaa]

that is too cool. looks like OJ footage.

[MetroMPG]

I have never had so many people want to talk to me about any car I've ever driven.

Today, two people came over to talk to me within 10 minutes. Even on the road, people roll down their windows beside me in traffic to ask about it. I saw a guy pull over to the side of the road to let me go by so he could pull out behind and get a better look.

My favourite so far: one guy literally ran out into the middle of the street, waving his arms for me to stop so he could find out about it. OK, so he was also drinking beer. But still, full points for enthusiasm!

Also memorable: a gaggle of school kids (let's say grade 6 or 7) -- 2 boys and 2 girls -- seemed so excited about it that at first I was sure they were just taking the piss outta me, as a Brit might say. But they kept asking legitimate questions and in the end seemed seriously impressed by it. "That's so cool. You should sell those!"

Guessing game!

Lately, instead of just answering the usual question, "what is that for??", I've started a fun new game: Guess What that Thing is on the Back of My Car!

Guesses so far:

1) It's a fold-out tent for car camping.

2) It's extra fuel storage - auxiliary tank inside.

3) Added crumple zone!

4) Extra cargo space.


33% vs. 66%

I'd say about 1/3 of the people who have asked about the tail figured it out with no prompting. One older woman in particular was memorable. She was walking along a sidewalk carrying full bags from the grocery store and stopped as I rolled into a parking space downtown. (The engine had shut off as I slowed down to park.)

Question 1: "That's the quietest car I've ever heard. Is it a hybrid?"

Questions 2, 3 & 4 rapid fire: "What's that on the back? Aerodynamics? Is it for better fuel economy? "

Ladies and gentlemen, we have a winner.

---

Of course I've also seen what amounts to pointing and laughing. But those people don't come up and talk to me. I wish I knew what they were thinking too.

[MetroMPG]

Better late than never...

Originally Posted by planetaire

Do you have an idea concerning the weight ?

Checked this weekend: 19 kg / 41 lbs

[California98Civic]

Originally Posted by MetroMPG

... But... decent results! I'll post them soon, but I make no promises it'll be posted today or this weekend.

Though I see you have a lot going on with this car already (DRONES?!), I would love to see these results from your testing.

[MetroMPG]

Yeah, I was busy getting more video this weekend...



Quick results... I have only entered the "A-B non-tail mods package" test so far (grille block, passenger mirror delete, driver's mirror folded, wheel discs, rear skirts, rear smooth undertray, rear wiper delete), and it showed +7.5% @ 65 mph / 105 km/h. The tail A-B-A numbers showed an additional ~10% @ the same speed, but that number is from a quick calculation. I haven't actually stuck the run results in the spreadsheet yet.

So this message may self-destruct when I post the full, double-checked results.