Anyone know if you increase your tire size (235/75R15 to 265/75R15) and by a little bit of weight (29 to 38 lbs.), if that will cause a significant problem in alignment? I was also told I'd see a huge difference in fuel economy. Is this really due to the weight of the tire? (It's only 40 more lbs. total).

 

[updated:LAST EDITED ON 26-Nov-01 AT 05:22 PM (EST)]Couple of things to toss your way, the extra weight will have several effects. First, mileage, this will go down slightly. The reason being that there is now more weight to get moving and keep moving, but as you pointed out, not really that much difference. Please keep in mind that braking will be effected in the same mannor, again, not much. However, you will have a little more rubber in contact with the road. One other note, your speedo will now be off by a percentage that is direct to the percentage of the rolling radius difference (measured with the tire on the ground to the center of the hub or axle) between the two tire sizes-this will help with mileage a little when "corrected" for miles travelled. Second, and I'll lump a few of the suspension items for this, alignment may suffer easier when you hit a large pothole, bottom line, more weight=more leverage. You may have to obtain heavy-duty or gas charged shocks, they now have to control this extra weight and as such ride quality may suffer, but will be offset somewhat by the increase in sidewall and the larger footprint to absorb bumps. This will also raise the center of gravity of the truck, again, very little but may tend to feel a bit more top heavy. All in all, I really don't think you will notice much of a difference jumping sizes as you want to, now 33" tires would be a totally different story! If these tires give you the "look" you want and can live with a little "quirks", by all means go for it! One other thing now, I should mention maint.,just that you must keep in mind how much your speedo is off and calculate for scheduled service accordingly.

 

First a couple of questions???? What year is your truck? If it is 98 or newer then you have a torsionbar front end. I have a 98 4WD ranger with 31x10.50 all terrains on it. I also twisted up the torsion bars to get rid of that factory sloped nose that all fords come with( I just don't like it). The alignment was never affected with the torsion bars or the tires, If your truck is less than a 98, I couldn't say what it will do( there are 1.5 inch leveling coils for it though ). Another thing to look at is how your truck is geared, a friend of mine has a ranger with the 3.0 v6 also with 31 inch tires. His mileage went up with the larger tires while the truck was geared to low for the factory size. As for ride quality, I can't really say since the extra twist on my torsion bars make the front end a little more stiff. I lost about 50 miles to the tank for gas mileage, that's not that much in my book. The larger tires with their larger foot print gave me all the traction off road that I will ever need. I hope this info helps.

Stumpjumper