Jamie, You can use this site to calculate speed differences based on tire size. http://www.miata.net/garage/tirecalc.html The recommended tire size for our vans is 185/80-14 That size tire shouldn't result in a 20 mph error. The larger tire you are running should only impact your speed by 2.1 mph, so when you are going 60 mph, it would actually be 57.9 mph... a 3.5% too fast reading with non-stock tires. So, at 70 MPH, you would really be going 67.5. Back in the 80's when 55 was the legal limit, many of the vehicle manufacturers inflated the speed slightly. I believe the Vanagon speed is off about 3 mph at 60... so if you apply the engineered speed error with your tires, at 70 MPH, you would be about 64 MPH or so.
Jack R. 84 Westy Wolfie. -----Original Message----- From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Jamie Fitterer Sent: Monday, May 19, 2008 1:31 PM To: vanagon@GERRY.VANAGON.COM Subject: Tire Size for 84 Westy I am currently driving on LT 195 75 R14 tires. My speedometer is off by A long shot. I am cruising along thinking I am doing around 70 and really I am traveling 50 MPH. ANy suggestions on a good size 14 inch to run or any suggestions on how to adjust speedometer? I like the LT tires because they last longer with the extra weight on them. Not sure deciding to go with LT tires was a mistake. |
Please note - During the past 17 years of operation, several gigabytes of
Vanagon mail messages have been archived. Searching the entire collection
will take up to five minutes to complete. Please be patient!
Return to the archives @ gerry.vanagon.com
The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.
Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.