What is the factory tire/wheel combination for the V6 trucks? Mine was fitted with an aftermarket set when I purchased it, so I am not certain. Thanks...btw, I'm thinking of a 2001.

 

I think the base wheel/tire package was 235/70/16, but many (if not most) roll off the lot with 255/70/16 wheel and tire upgrade. When I got my '99, the 255/70/16 upgrade was a factory incentive (free) on the V6.

BTW, when I replaced my tires I went with 265/70/16, and noticed a loss in power and mileage. Charts on the web show the 265/70 is only 2% taller than the 255/70, but my Michelins tires are 5% taller than my stock Generals. If I had to do it over again, I would go with 255/70.

 

Dave,

Thanks for this reply. I picked my truck up at a Chevy dealer (of all places) while looking for something with more room for the kids and such. They dealer had thrown the 265/60/18's on there that looked great, but it took me a year of observing other trucks, driving mine, asking questions and noting my poor gas mileage to start putting the pieces together... these tires are too big.

More recently, a local dealer had a pair of 285/60/18's that I bought, as I needed a pair and figured putting these on the back would not be so bad. Now, a few months later...I'm thinking that they are bad. I'll have to check and see the size difference on one of these comparison charts between the factory size(s) you mentioned and what I have now.

Probably get some 16" wheels back on there. Need to just figure out what size compares to the 255/70's.

THANKS much!

 

Did some checking, looks like the 255/55/18 and the 265/60/18's are not too far off from the 235/70/16 and 265/70/16's...except for the prices of the tires...

 

i had 235/70R16's on mine. got a set of american racing rims the black nascar style ones in 16x8 and run 255/65R16 now. your door jamb sticker might show original tire size.

235 x .7 x 2 devided by 25.4 + 16 = 28.95 inch tall tire. this will give a good estamite of what your tire size is. if it came with 255/60R16 then tires would be 30.05 inches tall.

265 x .6 x 2 devided by 25.4 + 18 = 30.52 inches tall

255 x .55 x 2 devided by 25.4 +18 = 29.04 inches tall

 

Great math, never seen it calculated like that before. Thanks. Out of curiosity, what tire model/brand did you find in that 255/65/16 size?

 

yokohama geolanders, but there are more companies making them. they are stock size on various suv's the tire rack has a good way of looking up lots of different tires in a size catagory.

 

I ended up going with a 255/55/18, slightly smaller than the 265/60/18's that the dealer had installed. DEFINITELY smaller than the 285/60/18's!

The 255/55/18's are nearly the exact dimensions (except for width of course) as the stock 235/70/16's that would have come with the truck. What a significant difference!

My truck is lowered, so I had to install some wedges to get the driveline straight. Yet with the 285/60/18's on there, the truck was just U-N-H-A-P-P-Y. Some of the driveline groan came back and the get-up-and-go was sluggish to say the least.

It feels much better without the oversized tires on there. The combination of the large tire height and width, along with my truck being a supercab, was just not something my V6 liked very much.

My 2001 is smiling again.

 

Since the power on the V6 is a little sluggish, gear ratio also plays a big factor in performance.

If your truck has the 3.08 rear end, I can imagine performance would really suffer with the bigger tires. I think most of us have a 3.55 rear. If you've got the 3.08 rear and are running larger than stock tires, it might be worth it to change the ratio to a 3.55, 3.73 or even higher.

 

dbd,

Where can I look to find my ratio? Or do I need to do the "spin the drive shaft - count the tire rotation" thing to figure this out. Although I won't be bumping up to the larger tires any time soon, it would be good to know.

Also... what dealer set-up or place of origin (factory) might determine why any of these trucks had different gears? I figured that the V6's were geared differently, but never looked into it.

What I can say is this, be careful going with the big tire/wheel combination. It can make a SERIOUS difference!

Thanks-
Jeff

 

Sacto - If I remember correctly, the 3.08 was the standard, and 3.55 was a common and inexpensive option. I bought my truck off the lot and at that time almost all the V6 automatics on the lot had the 255/70/16 tire upgrade and 3.55 non limited slip gears.

I found cut and pasted the chart and sentence below from an old thread:


"Here is the list (from different F-150 site) of codes on the driver side door under REAR section. Look what matches to yours....

F-150:
19 – 3.55 Non-LS
18 – 3.08 Non-LS
H9 – 3.55 LS
B6 – 3.73 LS"

 

dbd,

I have a tag on the driver's side rear door, but none of these numbers are there. This tag has the tire specs, GV weight info, bar code, vin, etc... but I don't see any of that info. Direct me!

Also, still have to note, gas mileage is MUCH improved, very evident already (first full tank since changing the tires).

Jeff

 

Jeff,
On my '99 Supercab, there is a tag on the driver's side rear door. It is just below the latch on the 'edge' surface where the two doors latch together. On the lower part of the tag there is a heading for 'axle' and mine has '19' right below that.

It's a shame the mileage suffers so much when we get rid of our POS stock tires. I thought going to a taller 265/70 over the OEM 255/70 would help mileage after correcting for speedometer error. But the wider tires must have more rolling resistance, and it just takes more throttle to accellerate and maintain speed with the taller and heavier tires. Oh well - live and learn.

 

Mine looks like this:

R AXLE
9 27

27? What the heck does that mean?

 

Jeff - looks like they changed the codes between '99 and your '01. I searched on google and found this thread

http://townhall-talk.edmunds.com/dir...ew/.ef0741a/45

If you search down, it looks like your code is for a 3.31 rear gear.