Swapping back to stock rims. Testing MPG difference

For the last year and a half I have been maintaining and honest average of 45mpg. Sometimes during the summer I can hit a few 47mpg tanks and a fluke 50mpg tank on a long trip. Other than that I usually see 44mpg on the MFD. I have read all the articles on hypermiling and other techniques and some I apply and other I do not for safety and sanity reasons.

Today I drove my usual route to work and applied my usual techniques but I was suprised to see 49.1mpg on the MFD after parking at work. This may have been due to removing my subwoofer boxes (68lbs) and not draining the 12v battery the entire weekend. I have two high powered 10" subs and a 1500watt rms amplifier. Any other ideas?

So today I decided to swap out my 17" Centerline wheels and Kumho tires for the stockers to see if my milage goes up at all. After removing the Centerlines, I weighed them on a high quality scale we use for nitrous oxide refills. I was amazed to find out that the combination of a Kumho Ecsta ASX 215/45/17 wrapped around a 17x7 Centerline RPM wheel weighed a whopping 37.6lbs-38.2lbs! The stock 15" Prius wheels with Integrity tires weighed in at 31.5lbs. I had assumed the new combo was only 3lbs heavier than stock at the worst, not 6lbs. To be completely fair here, the stock lug nuts are probably double the weight of the Gorilla lug nuts I had on the Centerline combo but that may be splitting hairs. :lol:

So my first test will be the removal of the subwoofer boxes and riding on the stock wheels. Then I'll add the subwoofers back in and track the mpg effect that has, if any.

My point in writing this is to have a record of what I am trying and to let you guys with aftermaket wheels know how much of a potential difference they can make over stock gear.

 

<div class='quotetop'>QUOTE(apriusfan @ Nov 6 2007, 07:03 AM) [snapback]535480[/snapback]</div>

Thanks!

I'm going to refill the tank today before class and start fresh with the new wheels. What tires did you use again? Air pressure?

I filled the Integritys up to 48/46. My Kumhos were at 56/54 I believe.

 

The first morning with the stock wheels went well.

I started the day at 46 degrees. Drove 1 mile to the gas station and filled up the tank so I could get a fresh start.

If anyone is familiar with Rocklin/Lincoln area, my commute is on Highway 193 then Sierra College Blvd.

I then drove the 13miles to school which is partial residential (35mph limit), then highway mostly up a very slight incline (55mph limit), over one hill (not much ability to coast on the "school" side of the hill), then up another smaller hill to the school. In essense, this should be the worst part of my trip. I never get good milage going this direction even in the summer. I ended the trip at 50.1mpg.

The return home was still cool out at 63deg (at 6pm) but the hills allow me to coast quite a bit more and make up for the terrible trip in the morning. I ended at home with 55.8mpg on the screen.





I understand this is a very small sample (miles) but I've make dozens of similar trips this semester and even flat-land driving during 85deg heat and never gotten anything close to this kind of milage. I'm not going to jump to conclusions just yet but it seems like I was losing quite a bit of milage with my previous setup. For clarity, I am maintaining the same driving style I performed with the old combo. No extreme hypermiling techniques or much pulse and gliding except to try and keep the ICE off as much as possible.

The car's handling has taken a huge hit but I think I can deal with it.

 

<div class='quotetop'>QUOTE(galaxee @ Nov 6 2007, 07:02 PM) [snapback]535911[/snapback]</div>

I'm pretty broke and will be for awhile so I'll wear down these Integrity tires, which should take about 5k miles. I'll end up buying some LRR tires to replace them and most likely run the stock wheels until I feel I just need the extra bling during the summer. You have to floss the phat rims in Cali or the breezies won't look twice. :lol:

 

<div class='quotetop'>QUOTE(apriusfan @ Nov 6 2007, 07:49 PM) [snapback]535932[/snapback]</div>

I completely understand. 280 is like the Bay Area Autobahn! One of my club members is a CHP on that highway and we hear all kinds of stories of exotics racing each other. 65mph is too slow for that area.

 

Update on milage after two more trips to school then my long commute to work. I'm pretty excited to see these kinds of results given the low temps I am driving in which average 50degrees.

Taken this evening after a 70+ mile commute

 

<div class='quotetop'>QUOTE(apriusfan @ Nov 9 2007, 09:49 PM) [snapback]537614[/snapback]</div>

Considering your location I'd say you are doing great. I was averaging much worse and still happy. Hell if it were not for PC I would have been content with my MPG but seeing people like Tony tooling around at 60mpg+ got to me and I knew I could do better. Now I'm in video game mode and I have to get a higher score. LOL

 

<div class='quotetop'>QUOTE(htmlspinnr @ Nov 10 2007, 09:42 AM) [snapback]537703[/snapback]</div>

Thanks Rick. I may try that once ther experiment is done. Overall I don't mind these tires. Sure the car doesn't handle like it did with the aftermarket gear but I'm not bothered by it. It just looks 10x worse. lol



<div class='quotetop'>QUOTE(usbseawolf2000 @ Nov 10 2007, 09:19 AM) [snapback]537699[/snapback]</div>

Yeah yeah, I'm jealous. Hush.

 

<div class='quotetop'>QUOTE(apriusfan @ Nov 11 2007, 11:46 AM) [snapback]538008[/snapback]</div>

Don't do it man... Must resist. M U S T R E S I S T....... :lol:

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ Nov 13 2007, 01:11 PM) [snapback]539057[/snapback]</div>

I'm hoping to see those kind of numbers this summer but for now I'm pleased with low 50s. It is much better than low 40s or mid 40s if I really try. lol

Yesterday I filled up and drove like it was a normal car. I stayed at the speed limits, 35,55,65,70mph, but didn't try any gliding (I never P&G) but I may have been in stealth mode a few times. I left the screen on the consumption screen and didn't pay attention to anything but the road. I have 191miles on this tank and am at 50.8mpg. If I did this same style of driving before I would be at 44mpg most likely. So I won't claim any real numbers here but the tire/rim combo as well as the stereo had to have been hurting my milage pretty bad. I can also coast much easier now.