Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 12-05-2007, 02:36 AM   This thread is in the EcoModder Project Library | #1 (permalink)
Master EcoModder
 
Peakster's Avatar
 
Join Date: Dec 2007
Location: Regina SK Canada
Posts: 407

Red Jeep Patriot - '07 Jeep Patriot
90 day: 25.14 mpg (US)

Beige Ford Ranger - '95 Ford Ranger XLE
Thanks: 0
Thanked 2 Times in 2 Posts
Arrow Video: Can Skinnier Tires Increase Fuel Economy?

I remember back when I used to ride a bicycle (man that was YEARS ago; that's got to change) I noticed that the mountain bikes felt like they had more rolling resistance than the cruisning bikes with their skinny tires. This made me wonder if getting skinny 'donut' tires on my car would increase fuel economy.

I purposefully put the smaller tires on the rear so that my speedometer and gearing would remain the same as with the larger tires.

These are the documented results:


I should add that I don't use these tires on a regular basis because of their lack of traction, ride quality, and quietness.

Feel free to discuss.

  Reply With Quote
The Following User Says Thank You to Peakster For This Useful Post:
nigelcut (04-16-2016)
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 03-27-2008, 11:42 AM   #2 (permalink)
EcoModding Lurker
 
Join Date: Mar 2008
Location: Savannah
Posts: 23

2005 CivicEX - '05 Honda Civic EX
90 day: 37.26 mpg (US)
Thanks: 0
Thanked 0 Times in 0 Posts
I'm surprised this hasn't been discussed here yet. I've thought of going with a more narrow lighter rim/tire combo for the rear. Impressive gains with a small change shown in the video.
__________________
  Reply With Quote
Old 03-27-2008, 11:54 AM   #3 (permalink)
Liberti
 
LostCause's Avatar
 
Join Date: Feb 2008
Location: California
Posts: 504

Thunderbird - '96 Ford Thunderbird
90 day: 27.75 mpg (US)
Thanks: 0
Thanked 7 Times in 7 Posts
I don't know if a thread has been put up on the topic yet, but I know people have recommended them before. I don't remember if it was on GS or here, but someone put extremely skinny tires on their vx. 155/85/13 if I remember correctly.

Ofcourse you lose traction/stopping ability, though. I think a bigger question is what is a better choice: a wider LRR tire or a skinnier normal tire?

Good work, though.

- LostCause
  Reply With Quote
The Following User Says Thank You to LostCause For This Useful Post:
beluga (01-02-2014)
Old 03-27-2008, 12:01 PM   #4 (permalink)
Eco Noob
 
Doofus McFancypants's Avatar
 
Join Date: Jan 2008
Location: Tosev 3 - Atlanta GA
Posts: 293

Red Rover - '01 Nissan Altima GXE
90 day: 30.07 mpg (US)
Thanks: 5
Thanked 7 Times in 5 Posts
a timely topic - i was just looking for other wheels and tires for the rear of the altima as well. Equipt with 205/60 -15's. pondering going to a 175/55 - 17's so in can fit them under a cover in the rear and moon disks up front ( although i have only seen up to 16 for moon disks .

Would love to see data on LRR vs skinny tire. anyone have comparison?

steve
__________________
Steve - AKA Doofus McFancypants
------------------------------
"If there's a new way, I'll be the first in line - But it better work this time"

First Milestone passed - 30 MPG (city) 5/15/08
Best City Tank - 8/31/09- 34.3 MPG (EPA= 20)
Best Highway Tank - 5/20/09 - 36.5 MPG (EPA= 28)
------
In effort to drive less:
Miles NOT driven in 2009 = 648 (Work from home and Alt Transporatation)
  Reply With Quote
Old 03-27-2008, 12:03 PM   #5 (permalink)
Master EcoModder
 
metroschultz's Avatar
 
Join Date: Dec 2007
Location: Norfolk, Va. USA
Posts: 869

CPT SLO - '93 GEO Metro plainjane
90 day: 53.91 mpg (US)

SilverHairBeauty - '01 Toyota Avalon XL
90 day: 24.06 mpg (US)
Thanks: 14
Thanked 33 Times in 28 Posts
Send a message via AIM to metroschultz
?"Your Guess is as Good as Mine"?

I would believe that rolling resistance plays a part in the reduction factor,
BUT,
Don't discount the aerodynamics of the two tire styles.
OEM = taller, wider, more contact patch
Donut = shorter [slightly], narrower, less contact patch, and they present a round face to the wind.
OEM tires present a large flat face to the wind.
many variables in one component.
changing all those variables at once = big difference.
I have found a source fro 145 80R 13 tires.
when my current tires are worn out I will replace them with the 13's
Your video just pushed me over my decision hump. I was waffling because this change requires the purchase of new rims also.
But I haven't been to the bone yard in a while, they probly miss me.
Schultz
__________________


When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That's relativity.
Albert Einstein
  Reply With Quote
The Following User Says Thank You to metroschultz For This Useful Post:
beluga (01-02-2014)
Old 03-27-2008, 02:44 PM   #6 (permalink)
Batman Junior
 
MetroMPG's Avatar
 
Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,513

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 52.71 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car - '14 Mitsubishi Mirage ES (base)
90 day: 60.16 mpg (US)
Thanks: 4,058
Thanked 6,957 Times in 3,602 Posts
SPOILER ALERT:

Peakster'll probably be mad at me for posting the results here in the thread, but here's what he observed in an A-B-A test, with a pair of donuts (on the rear) for the B test:

A - 55.9 mpg (US) average (regular tires)
B - 60.9 mpg (US) average (donut tires)
__________________
Project MPGiata! Mods for getting 50+ MPG from a 1990 Miata
Honda mods: Ecomodding my $800 Honda Fit 5-speed beater
Mitsu mods: 70 MPG in my ecomodded, dirt cheap, 3-cylinder Mirage.
Ecodriving test: Manual vs. automatic transmission MPG showdown



EcoModder
has launched a forum for the efficient new Mitsubishi Mirage
www.MetroMPG.com - fuel efficiency info for Geo Metro owners
www.ForkenSwift.com - electric car conversion on a beer budget
  Reply With Quote
The Following User Says Thank You to MetroMPG For This Useful Post:
nigelcut (04-16-2016)
Old 03-28-2008, 01:05 AM   #7 (permalink)
Who
UnderModded
 
Join Date: Dec 2007
Location: San Jose
Posts: 319

Pablo - '07 Hyundai Santa Fe AWD
90 day: 23.62 mpg (US)
Thanks: 0
Thanked 2 Times in 2 Posts
I'm looking at narrower but heavier and taller tires.

Current tires are 235/70R16s which are 29.1" tall and 32 pounds rated at 44 psi and driven at 55 psi.

I'm looking at replacing them with 215/85R16s. They tend to run around 30.4", 0.7" taller and about 4½% more gearing which should nullify the speedo error. Nearly all models are heavier. Some as much 47-48 pounds. The weight wouldn't help in the city stuff. Rotational mass is the bane of all cyclists.

The D rated tires in this size are rated to 65 psi and the E rated tires 80 psi. It would be nice to get rolling resistance and noise specs...

Think they'd help? The aero could get worse from the vehicle being even taller. The gearing change should be minimal but help on the hwy unless lost to aero. They take mega PSI...
__________________
  Reply With Quote
Old 03-29-2008, 07:20 PM   #8 (permalink)
Who
UnderModded
 
Join Date: Dec 2007
Location: San Jose
Posts: 319

Pablo - '07 Hyundai Santa Fe AWD
90 day: 23.62 mpg (US)
Thanks: 0
Thanked 2 Times in 2 Posts
No opinions?
__________________
  Reply With Quote
Old 03-29-2008, 08:03 PM   #9 (permalink)
OCD Master EcoModder
 
brucepick's Avatar
 
Join Date: Dec 2007
Location: Eastern CT, USA
Posts: 1,933

Outasight - '00 Honda Insight
Team Honda
Gen-1 Insights
90 day: 54.18 mpg (US)
Thanks: 429
Thanked 391 Times in 261 Posts
Who - re. tire size change.

Take a step back - you mentioned speedo error. Do you have an error now and the taller tire should correct it? That would be nice.

Some thoughts re the tradeoffs with the larger tire:

It's taller so raises car so aero gets worse.
But remember, .7 inch bigger diam. means the car will be .35 inch higher. Yes, .35 inch raise is not ideal but maybe not as significant as the other gains you'll get.

Tire is heavier:

I think the large weight increase will hurt you. But read on, I think there's hope...
A larger tire will be heavier but if tire is taller and also skinnier I don't think it has to be that much heavier than your stock tire, and maybe not heavier at all.

What I'm getting at is I think the tire(s) you've found are rated for a much higher load capacity and so are built with a lot more beef. Probably pricier too. If you find tires with similar load rating and spec'd for 44 psi they'll likely weigh similar to what you have now. You can still run the 44 psi tires at 50-55. If you want more, maybe go to a tire rated at 52 to 55 psi and I'd think you can run it at 60-65-70 psi without worry, if you can stand the hard ride.

Oops - I just noticed you're driving a Santa Fe. Anyway, do look up the orig spec tire and its load rating. No need to get a tire built to carry 50% more weight than OEM spec unless that's how you load up your vehicle.
__________________
Coast long and prosper.
Driving '00 Honda Insight, acquired Feb 2016.


  Reply With Quote
The Following User Says Thank You to brucepick For This Useful Post:
nigelcut (04-16-2016)
Old 03-29-2008, 08:38 PM   #10 (permalink)
EcoModding Lurker
 
HotRod's Avatar
 
Join Date: Mar 2008
Location: Idaho
Posts: 27

HotRod - '94 Geo Metro Reg
90 day: 58.89 mpg (US)
Thanks: 0
Thanked 0 Times in 0 Posts
This is probably a totally dangerous/unfeasable option, but I was at the Lowes the other day and walked past their trailer tires. 12" just like the metro, but skinny, and a VERY high psi rating. ??? ummm...to bad they were a 5 lug.

__________________
I am not a Hippie...I am cheap.
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Search Engine Friendly URLs by vBSEO 3.5.2
All content copyright EcoModder.com