Tires, Wheels, Backspacing and Offset?

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Jun 4, 2007 | 12:15 AM

Benjoman

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From: South Florida

Tires, Wheels, Backspacing and Offset?

I would like to get some new rubber for my EX. I currently have Firestone Transforce HT 265/75/16s on stock 03 EX Ltd. wheels. The PO said they were the ones installed after the recall. They are load rating E. I have installed new V & F code springs, rear Helwig Anti sway bar, and Rancho RS9000X shocks. The ride is good except the tires seem quite harsh going over small bumps and roadway seams etc. Does anyone else have these Firestones and find them hard riding? I had 65psi in the rear and 60 in the front while towing my 6000lb. trailer. Back home now I have reduced it to 50psi all around and that helped some. I would like to get a little larger tire and/or wheel. Some posts I have found say you can mount 285/75/16s on stock rims, others say you should go to 8 inch wheels since they require a minum of 7.5in. and stock EX rims are only 7in. Any thoughts on this? If I get new wheels I need to know the correct offset and backspacing. Does anyone know these dimensions for our stock wheels?

Thanks in advance for any suggestions.
Ben

Jun 5, 2007 | 02:06 PM

Benjoman

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From: South Florida

I don't know what the biggest mystery is, whether no one knows the backspacing and offset or why no one will even view my post??

Jun 5, 2007 | 03:37 PM

hungry_aggie

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I have a 03 with 285/75/16 d rated bfg at's on stock rims they fit great wear even and ride great. I originally had 265/75/16 e rated bfg trail ta's the ride was worse than my 94 f350 4x4 witch rides like a tank. I run 60psi all the way around. You only lose 150# of rated capacity per tire if you go up to the 285/75/16d vs the 265/75/16e tires. I still pull a 9500# tt just air the tires up to max when i do no problems so far I have 38,000 miles on them not even half the tread gone.

03 EB 4x4 6.0td X
94 f350 crew cab 7.3td(non powerstroke)
97 f150 extened cab 4.6

Jun 5, 2007 | 06:54 PM

VaSheriff

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Quote:

Originally Posted by Benjoman

I don't know what the biggest mystery is, whether no one knows the backspacing and offset or why no one will even view my post??

The offset does indeed seem to be a mystery in most circles.

Here's a quote from an eBaY auction.....

Up for bid in the Atlanta, Georgia area, this set of 4 late model Ford OEM Super Duty F-250 , F-350 or Excursion 8 lug factory polished alloy16 x 7 inch wheels, with caps and 32 lugnuts. The backspace about 4 3/8 inches, bolt pattern is 8 x 170 mm or about 6 5/8 inches. The center hole is about 4 7/8 inches. They are marked 16 x 7K with Ford part number F81A-1007-MA., if I am reading it correctly.

And another quote from an eBaY auction...

Bolt Pattern: 8 x 170
Size: 16 x 8
Offset: -4 mm

And another......

Wheels Manufacturer / Model: Ford OEM
Wheels Size: 16x7

Wheels Lug / Bolt Pattern: 8 on 170mm

Wheels Back Space: 4 3/8 Aprox.

Wheels Finish: Polished Alloy

Wheels Condition: Please see the attached pictures<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o><o></o>

Caps: Included Choose between Closed or Open Caps, just let us know your needs.

These Wheels will fit the following 8 Lug/Bolt Patternvehicles: <o></o>

Jun 5, 2007 | 10:22 PM

Benjoman

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From: South Florida

H Aggie
Thanks for the input. That reinforces my own thoughts that I may get a better ride out of D rated tires and their load limits of approx. 3000lbs should more than meet my needs.

Va Sheriff
Thanks for the info. Thats the kind of lack of specifics I've been encountering. I did get one bit of data from another source which indicated some manual specified an offset of .25in

Ben

Jun 6, 2007 | 08:12 AM

hungry_aggie

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looked up the tire specs last night

285/75/16 d bfg at's 3305# @ 65psi
265/75/16 e rugged trail ta's 3415# @ 80psi

Thats only 110# per tire at a lot less psi.

my speedo is off about 3mph and I did lose about 1 mpg when i went to the bigger tire but well worth it still got 18mpg average on last two trips to taos New mexico skiing with the family for spring break about 2500 miles total on each trip.