305/70 r16

[BugBuster]

I have a 2001 gmc regular cab z71 that I hunt out of and was thinking about going from 285's to 305's. Anybody running the 305's? How much will they hurt the power and fuel mileage?

[adk]

Ducks Unlimited on this site has 305's. I can feel much of a difference at all power wise, i dont think he lost much fuel economy either.

Bump it any bigger than that, and youll either have to re-gear it or loose power.

[adk]

just for shits and giggles, why are you bumping up? Just looks or what?

[BugBuster]

Looks and ground clearance.

[Southernduck]

we run 305s on our suburbans. they really arent any taller than 285s they are an inch wider though. dont notice a loss in power but couldnt tell you about mileage cuz those suburbans get such shitty mileage we quit looking

[Phone Man]

305/70 16's are 33 12.50 16 equivalent. 285/75 16 are 33 11.50 16 equivalent. They are supposed to be the same height just about and inch difference in section width.

the 305 number is the section width in milimeters. the 70 is the percentage of 305 and is the distance between rim and top of tire, or in other words=sidewall height.

Sidewall height for 305 X .70 = 213.75

Sidewall Height for 285 X .75 = 213.5

Therefore they are very close to the same height so they should not throw off your speedometer at all and the only thing that might affect mileage would be the 305 may be a little heavier due to more rubber from width.


Sorry for the long response, but hope this explains it for ya.

[Whackumstackum]

The 305 really dont give you that much more ground clearance than the 285's since they are the same height. They are wider so if you put them on a stock rim they will be just a tad higher. I had some on my truck but 2 where out of round and i had them order me a set of 285s when they replaced them for free. They seemed to wonder on the road a little more due to the added width. If I was going to go to a 305 again I would just get the 315's instead if you have the truck leveled out because they look really good on one of my buddy's trucks, z71 leveling kit, dont rub a lick, and the power difference between mine with the 285's and his with 315 is only slightly noticable but his truck looks alot more bad ass.

[smalltownz71]

I have a 06 chevy z71 with 305 bfg mt's. Didn't loose any power, and not enough mpg for me to notice. My next step is the full leveling kit with 315's.

[buckshot1224]

Go with 285s...........cheaper and less road friction because of the slight difference in width. If you want to cram some tires on it look it cranking the T-bars all the way, trimming the valances and slap on some 295/75s. They will fit but they will be TIGHT with very little available flew. 305s will rub when they are new on stock rims, BTW. Not much but they will a little on the control arms.

[adk]

come on yall, theres no rub to 305's. Now put some 36''s on stockers with just t-bar crank, thats rub, but 305s, nah.

[SCTIMBER]

Crank them t-bars all the way and you are asking for trouble. I ran 285's for a good number of years and recently went back to 265's. Friend of mine runs 315's on a GMC 2500, and I wouldn't have his truck if it was given to me ...crappy ride.

[Ducks Unlimited]

305's fit easy, I know guys with 37's with just the bars cranked, I know that's way too big of tire for a stock truck but it gets the point across. Trust me you will be fine with 305's and you would still be fine with 315's and a little trimmage. Almost all 315's don't measure anywhere close to a true 35 inches anyways. You will also be fine power and milage wise with 305's.

[killindux843]

I have 315s on a z71 and it didnt seem to hurt the power on bit. i turned the torsion bars up and put shocks on it. It is not that bad of a ride.

[Chuck the Duck Slayer]

went from 245 65 16 to 285 70 17's on my 2500 duramax and before the reprogram it took a little from my fuel mileage but I got it back with some different programs.

[BugBuster]

Thanks for the info. I would have never thought 295's would be taller than 305's. Anyway I do alot of driving will probably go ahead and run my 285's on thru hunting season. It sounds like I won't accomplish much with 305's and I think 295's or 315's will hurt my power and mileage. I commute about 60 miles a day so mileage does count.

Is there any other all terrain tire that ya'll like besides bfg at's? I have them on another truck and love them, but the price hurts.

[adk]

Look at Procomp A/t's. nice tires if youre gonna go A/T.

[Ducks Unlimited]

toyo and nitto all terrain's arent bad. mickey thompson atz's are cool but they might be too aggresive for what you want

[smalltownz71]

All the ones that DU stated are great tires, but can be kinda pricey. A good one to look at that im goin to next is the Mastercraft Courser CT's.

[wdhigh]

Nitto 285/70/17 a/t at tire kingdom were like $130-$140 2-3 months back. I hear they require little to no weight to balance, just what the guys mounting them said? Nobody had commented on mileage with the a/t's, and the nitto m/t are awfull quick to burn up. One thing strange to me is they are blackwall only. I like to leave the blue crap on the white letters for a while so all my homeys know I gots new "white walls"!


Bfg has done something to there tread compound. Mine are wearing like crazy and I have had the alignment checked and rotate every 5k miles.

[buckshot1224]

I don't much about any A/T other than BFG but as far as an aggressive tire for the money is a Mud King. I haven't had any but I know a ton of people that have and it seems they are getting about 30K-40K miles out of them.