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Discussion Topic:
Another Tire Question
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Dream38v8 |
12-14-2020 @ 12:26 PM
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New Member
Posts: 178
Joined: May 2016
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Reading the note on radial tire size got me thinking about my tires. I will be replacing tires on my '38 Deluxe fordor in the spring. I have decided to go with basis ply vs. radial. Additionally I am seriously considering Lester tires or Diamond Back. Lester Tires were on the car when I purchased it in 2016 and there have been no issues. My logic behind my decision is based on cost and miles driven per year (1000+) for the last five years. Very little driving is at highway speeds even though the '38 has no issue getting to 60. I was looking to go one size larger at 6.50x16 vs. 6.00x16. To my knowledge the wheels could be original. So is there any issue with moving up to 6.50x16? Thanks
Ray
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sarahcecelia |
12-14-2020 @ 1:15 PM
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Senior
Posts: 1194
Joined: Mar 2013
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They are only 50/100 ths. wider; that's not much
Regards, Steve Lee
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TomO |
12-15-2020 @ 6:38 AM
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They should fit your car OK. You will have some speedometer error and slow speed turning issues that could be significant to some people. When I went to the larger size, I went from Lester tires to Firestone and did not notice any change in steering effort.
Tom
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Steve Kennedy |
12-16-2020 @ 7:26 AM
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Posts: 64
Joined: Jul 2017
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I have 6.50x16s on the back of my '36. I also have an ap that grand son downloaded on my phone which shows my exact speed. At 60 on my phone, I am actually going just a little faster, like 63. Speedometer bounces around some times so it is hard to tell.
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sarahcecelia |
12-22-2020 @ 1:47 PM
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Senior
Posts: 1194
Joined: Mar 2013
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Tire width has no effect on the speedo. That only comes into play when you change the diameter.
Regards, Steve Lee
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ford38v8 |
12-23-2020 @ 12:23 AM
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With regard to previous contradictory posts regarding speedometer error, the following facts are presented for those who value documentation over opinion. From the Ford V8 Service Bulletins: 6.00 x 16 tire Approximate loaded rolling radius: 13.38" Approximate revolutions per mile: 740 6.50 x 16 tire Approximate loaded rolling radius: 13.60" Approximate revolutions per mile: 722
Alan
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sarahcecelia |
12-27-2020 @ 2:30 PM
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Posts: 1194
Joined: Mar 2013
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That may be true, but that's not going to be very noticeable on the speedometer! That's only 18 revolutions per mile ! The speedometer might be off a half of a NEEDLE WIDTH!! Regards, Steve Lee
This message was edited by sarahcecelia on 12-27-20 @ 2:34 PM
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ford38v8 |
12-27-2020 @ 3:43 PM
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Again, that's only your opinion. Do the math. Alan
This message was edited by ford38v8 on 12-27-20 @ 3:44 PM
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kubes40 |
12-27-2020 @ 4:51 PM
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Alan, you are of course 100% correct in your previous post. I install 6:50's on all of my restorations. They were an optional size in '39 as well as '40. In my opinion, they simply look so much better than the (too) small 600's. The difference between the two in real numbers? The 6:50 is 29.1" tall, while the 6:00 is 28.3" tall. The 6:50 has a tread width of 5.1" while the 6:00 has tread width of 4.13". Realistically, my restorations rarely, if ever, get driven so I can't comment on how far off the speedometer is with this larger tire. However, I'd also installed 6;50's on my '36 roadster (my "driver") and have found the speedometer off by approximately 3 MPH when running at 55 + /- mph. So yes, as you'd stated previously, it does make a difference.
Mike "Kube" Kubarth
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ford38v8 |
12-27-2020 @ 5:28 PM
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Posts: 2780
Joined: Oct 2009
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Mike, Several people including yourself have noted an approximate 3 mph difference. You have furnished diameters of the two sizes, and Ford published loaded radius figures. I'm wondering then, am I not doing the math correctly, as I come up with a 1.5 mph difference? I'm thinking that loaded radius must be a static measurement, while the rolling dimension would be closer to the actual. Who knows? Maybe Ford didn't do the math correctly!
Alan
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