94 Tire Size

[Jez]

Hey Guys New to this site and new to Ford Trucks. I have a 94 F150 5.8 Reg Cab with the E4OD. Going to need new tires at some point and i was wondering the pros/cons to getting a larger size. The truck is not my daily driver, I use it for towing my boat. I want to have good wet/snow traction. Thanks

[StrangeRanger]

What rear end ratio do you have?
It matters as to which tires you can use

[Jez]

The Axel code is 18. I believe that's 3.08

[StrangeRanger]

18 is a 3.08 and taller tires will reduce your towing and your performance. You're basically undergeared already, they'll just make it worse.

[Steve83]

I run 33" tires with 3.08s, a 4.9L, an NP435 (no OD), and a heavier truck, and it works fine for me, all the way up to ~110mph.

But I don't recommend 33s for towing - the sidewall is too big to control a trailer. There's nothing wrong with the stock tire size, and it's probably the best for towing. Bigger tires don't help on-road in snow or rain. Good tires can, so buy high-quality stock-size all-weather tires. Something like BFG AT TA KO, or Michelin LTX AT.

[Jez]

Thanks. Sounds like i should stick with the stock tire size.

[es347fan]

I've been running 255/70-15s for years. Truck originally came with General Ameriways 235-75. They were hard as rocks and permitted the rear end to dance whenever they hit a puddle. I dumped them after about a year & went to Dunlop GT Qualifiers. Those are rated to carry the exact same weight as the Generals, but at a much lower psi. The 70 series adds a bit more flex and the 20mm of extra width is welcomed.
I now have 160K on it and put its 5th set of tires on in 2008.
That truck has been in every kind of weather, from years in south Texas and even a few in western NY state. The tires have not been an issue. It's just a street truck, not a 4x4 woodland wanderer.
Learn to read the tire sidewall. You'll want a good all-season tire with high numbers in treadwear and traction.

[Steve83]

70 isn't a series; it's the nominal aspect ratio of the sidewall to the tread width. So the original sidewalls were 235mm x 0.75 = 176.25mm tall, and the new ones are 255mm x 0.70 = 178.5mm, so somewhere around 2.25mm taller than the old ones. That's not enough to notice on a new pickup; much less a 21-year-old. But the width WOULD be appreciable.

[es347fan]

Originally Posted by Steve83

70 isn't a series; it's the nominal aspect ratio of the sidewall to the tread width. So the original sidewalls were 235mm x 0.75 = 176.25mm tall, and the new ones are 255mm x 0.70 = 178.5mm, so somewhere around 2.25mm taller than the old ones. That's not enough to notice on a new pickup; much less a 21-year-old. But the width WOULD be appreciable.

That's where you're wrong, Steve83.

Do a google of 70 series tires and among the 311,000 hits you'll find one that reads thusly:

What size do you need? The easiest way to determine size is to look on the side of your current tires. The information is also listed in the owner's manual along with alternate sizes that will work on your vehicle.
Size refers to the combination of tire width, aspect ratio and rim size.
The first number (175, 185) is a P-metric designation that refers to the width of the tire.
The second number (70, 75) is the aspect ratio and is also called series.
The third number (14, 15) refers to the diamenter of the rim.

In common, every-day American English, if one walks into a tire-selling establishment and says they need "...70 series tires..." any individual they will encounter working there will know exactly what they are talking about.

Right?

I'll be happy to play word games with you anytime you choose.

[Steve83]

You can find 100 million people who call a starter relay a "solenoid". That doesn't make it a solenoid. So if you want to call the aspect ratio "series", "solenoid", or "Gretchen", it won't bother me. I didn't tell you not to - I just said it's NOT a series.

Words already have meanings, no matter how many people use them incorrectly.

[es347fan]

The second number (70, 75) is the aspect ratio and is also called series.

Are you purposely being obtuse?

[buckdropper]

[Steve83]

No, but I'm through trying to get my point across to you. Call it what you want.