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

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 09-14-2016, 01:32 PM   #1 (permalink)
EcoModding Lurker
 
Join Date: Jul 2016
Location: Surrey, BC
Posts: 10

Tealo - '91 Honda Civic DX
Team Honda
90 day: 34.88 mpg (US)
Thanks: 2
Thanked 7 Times in 1 Post
Tire size confusion

So I've realized that the tires on my car are not stock size which would mean my speedometer and odometer readings are slightly off.

My car's stock tires would be 175/70R13 and the ones on my car are 195/60R14.

When I plug those numbers into this site it says when the speedo says 100 I'm actually going 102.5.

However, when I use the calculator on this site it says when the speedo says 100 I'm actually going 97.56.

Not sure why I'm getting different numbers here. Any help would be appreciated, thanks!

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 09-14-2016, 02:28 PM   #2 (permalink)
Red Light Avoider
 
pletby's Avatar
 
Join Date: Jul 2010
Location: Winnipeg, Manitoba, Canada
Posts: 296

My Civic - '00 Honda Civic DX
Team Honda
90 day: 46 mpg (US)
Thanks: 114
Thanked 47 Times in 34 Posts
If you have a GPS or even a cell phone with GPS you can set your cruise at 100km/hr and read how fast you are really going then apply the correction to your speedometer.

As a strange sidebar my speedometer is optimistic by around 4km/hr, but when I read the speed off my Ultragauge accessing my car's computer it matches the GPS exactly. Weird eh?

I'm not an expert on reading tire sizes, someone else will chime in I'm sure.
__________________


  Reply With Quote
Old 09-14-2016, 02:52 PM   #3 (permalink)
Karmann Eclectric
 
jray3's Avatar
 
Join Date: Feb 2010
Location: Graham, WA
Posts: 149

Odysseus - '00 Honda Odyssey

MR BEAN - '12 Mitsubishi i-MiEV SE

Karmann Eclectric - '71 VW Karmann Ghia Electric Conversion

BOB - '87 Ford 250 Lariat ext cab
Thanks: 9
Thanked 72 Times in 42 Posts
Honda speedo= wierdo

I've seen bad speedometer readings on two hondas now (with stock size tires). My Odyssey reads 4-5 mph high at highway speed, but the odometer and OBD readouts are spot on, whether counting mile markers or using GPS.
__________________
2012 Mitsubishi i-MiEV, 112 MPGe
2000 Honda Odyssey
1987 F250 Diesel, 6.9L IDI, goes on anything greasy
1983 Grumman Kurbwatt, 170 kW "Gone Postal" twin
1983 Mazda RX-7 electric, 48 kW car show cruiser
1971 VW Karmann Ghia electric, 300 kW tire-smoker
1965 VW Karmann Ghia cabriolet, 1600cc
Have driven over 100,000 all-electric miles!
  Reply With Quote
Old 09-14-2016, 03:10 PM   #4 (permalink)
Master EcoModder
 
vskid3's Avatar
 
Join Date: Jun 2008
Location: Utah
Posts: 886

Civic DX (sold) - '97 Honda Civic DX
90 day: 34.15 mpg (US)

GTO (sold) - '04 Pontiac GTO
90 day: 22.62 mpg (US)

Green Brick (sold) - '06 Ford Escape Hybrid
90 day: 31.93 mpg (US)
Thanks: 168
Thanked 271 Times in 194 Posts
I think your issue is that the two sites compare things backwards from each other. Your second site is actually saying that when your speed is 100, your speedo will say 97.56. The tire you're running is a little bigger, so you'll go farther for each revolution compared to the stock size. That means your speedo will read lower than actual (or at least lower than it would read compared to the stock tires). GPS is the way to go, especially to check the odometer (more important for MPG calculation).

Quote:
Originally Posted by pletby View Post
As a strange sidebar my speedometer is optimistic by around 4km/hr, but when I read the speed off my Ultragauge accessing my car's computer it matches the GPS exactly. Weird eh?
A lot of cars will read a little high on the speedometer, but the odometer and speed from the OBD-II port are right on. Supposedly it's so you can't blame the manufacturer if you get caught speeding.
__________________
Current cars:

Prius Thread

Volt Thread


E-Bike Thread
  Reply With Quote
Old 09-14-2016, 03:24 PM   #5 (permalink)
.........................
 
darcane's Avatar
 
Join Date: Aug 2009
Location: Buckley, WA
Posts: 1,572

Ninja 650R - '06 Kawasaki Ninja 650R
90 day: 52.02 mpg (US)

B*tch - '01 Honda Civic HX
Team Honda
90 day: 38.09 mpg (US)

Ms. Hyde - '06 Cadillac CTS V
Sports Cars
90 day: 16.93 mpg (US)
Thanks: 365
Thanked 472 Times in 306 Posts
Quote:
Originally Posted by homeiss View Post
So I've realized that the tires on my car are not stock size which would mean my speedometer and odometer readings are slightly off.

My car's stock tires would be 175/70R13 and the ones on my car are 195/60R14.

When I plug those numbers into this site it says when the speedo says 100 I'm actually going 102.5.

However, when I use the calculator on this site it says when the speedo says 100 I'm actually going 97.56.

Not sure why I'm getting different numbers here. Any help would be appreciated, thanks!
Both answers are identical, just inverted in how they are displayed... change the order you plug them in and you will get the same numbers.

Ignore the numbers for a moment. Your current tires are taller than stock. Because of that, you are going faster than you would be going with the stock tires.
__________________
CTS-V


Past Cars:
2001 Civic HX Mods

2003 Silverado Mods
  Reply With Quote
Old 09-14-2016, 03:30 PM   #6 (permalink)
EcoModding Apprentice
 
iveyjh's Avatar
 
Join Date: Apr 2011
Location: Canyon Lake, Texas
Posts: 221

none - '98 Honda Civic HX

none - '00 Chevy (Geo) Metro base

none - '00 Saturn SL1 base
Thanks: 123
Thanked 73 Times in 47 Posts
The second one is correct, all things considered.
  Reply With Quote
Old 09-14-2016, 04:38 PM   #7 (permalink)
EcoModding Lurker
 
Join Date: Jul 2016
Location: Surrey, BC
Posts: 10

Tealo - '91 Honda Civic DX
Team Honda
90 day: 34.88 mpg (US)
Thanks: 2
Thanked 7 Times in 1 Post
Thanks everyone. So does that mean I can just multiply the odometer by 2.5% for correct readings?

I'll try downloading an app to check my gauges with as well.
  Reply With Quote
Old 09-14-2016, 09:47 PM   #8 (permalink)
Aero Deshi
 
ChazInMT's Avatar
 
Join Date: Jan 2010
Location: Vero Beach, FL
Posts: 1,058

MagMetalCivic - '04 Honda Civic Sedan EX
Last 3: 34.25 mpg (US)
Thanks: 430
Thanked 658 Times in 352 Posts
I have noticed that tires of the same size by differing makes have slightly different diameters when I shop on Tire Rack.I ALWAYS use Tire Rack as a guide for the tires I'm going to buy for my cars since 1992 or so to get the best price. When they started putting performance and review ratings up it is just an amazing site to find the best value. I would never have bought General tires were it not for them.
  Reply With Quote
Old 09-14-2016, 09:54 PM   #9 (permalink)
EcoModding Lurker
 
Join Date: Jul 2016
Location: Surrey, BC
Posts: 10

Tealo - '91 Honda Civic DX
Team Honda
90 day: 34.88 mpg (US)
Thanks: 2
Thanked 7 Times in 1 Post
Ok so I ran a GPS speedometer app on my way home today. The second site appears to be right while the speedometer says 100 the app was saying around 97.5 km/h.

I reset the tripmeter and the car says 38.7 while the app reports 38.67, so almost bang on.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2018, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com