HOHN

I can't make up my mind.

I really would like the taller gearing of the bigger rubber, but they are $40 more each, and I doubt they would last as long.

Besides, since I rarely off-road, I'd probably have even better traction with the M55s, not to mention longer life.

How long are the 315 Toyos lasting?

I have the factory alloys, so I can mount either size on my stock rims.

Thanks.

Justin

Fishin2Deep4U

I like the M-55s on stock wheels and 315 on 9" wide sheels. JMO. But I think the wear is much better.

I am starting to look at 18x9 wheels now as my M-55s could use replacing. Only 60K out these and probably only 15K left.

WHAT JUNK!!!!

Dave

HOHN

Tally one vote for M55s since replacement wheels aren't in the near term budget.

Then there's always the 17x8.5"option that opens up a whole world of tire sizes, from 265 to 37"!

37s on 3.54 gears? Probably not so good

Fishin2Deep4U

I didn't even like the 315 with 3.54s in my truck. Although, I do want to go to that size.

Maybe with a 3.73 gear.

Dave

HOHN

Yeah, but I have a tranny that might let me get away with it-- and I almost never tow.

jh

1BAD4X4

HOHN, I remember you posting about some picture saying how you loved the look of the 315s, go for it if the price of fuel isn't a major concern. I used to get anywhere from 18.5 to 21 mpg with my 265s and I'm now averaging a mid-13 mpg rating with 315s. Now I know there are lot of factors to milage, but obviously you know they'll hurt it to a degree. But that doesn't mean I'm saying get the 285s, b/c I think all Dodge 2500s look terrible with any size tire under 285 size and thats pushing it depending on tread pattern. 315s just have a look and a stance that intimidates. Besides, you don't tow much... after owning 315s... I won't go back for anything. I'll suck up the fuel prices... even if #1 is $3.89/gallon........





Oh and, btw... 315s, stock tranny, 3.55s = not so much fun and kinda slow... but atleast its an excuse to get go fast parts.

Philabuster

I upgraded to Toyo 315 M/Ts about a month ago from the 255/85-16s the truck had when I bought it. The truck already had the 5" lift as well. The 255s looked tiny under the aftermarket fender flares and 5" lift. The 315s REALLY completed and complimented the look of my truck.

That said, my mileage went down about 0.5 to 1 MPG mixed city and highway (was 17.8, now about 17.0) with my Smarty on #9.

The gearing changed by about 1/2 a gear on the 6 speed. I cannot comfortably start out in 2nd anymore without needing a bit of clutch. I used to just dump the clutch when starting out in 2nd gear, but now I need to feather it a bit. If I was rolling along at anything above 5 mph, I would be in 3rd no problem, but now I need to downshift to 2nd or I lug the engine too much. Getting into 2nd gear is not as easy as 3rd.

Freeway driving, I feel like I am lugging the engine at any speed below 60 MPH in 6th gear. My new tires really make me want to do 75 MPH all the time (about 1,950 RPMs) on the freeway.

I will likely be towing my newly purchased toyhauler (10,000 GVW) at 60-65 in 5th gear instead of 6th.

I think the 315's and 3:73s would be a perfect combo for me. Would I get this size again? I'm not sure yet, but they do look good.

Maybe my opinion will change when I drop in some Mach 4s.

HOHN

I'm honestly not concerned with having enough bottom end grunt to launch. My current power combo gives plenty of takeoff power.

The difference in revs from a 265 to a 315 is right around 9%. That means where I'd normally be at 2000 rpm, I'd be 180 rpm less. To me, that's not a significant detriment.

This way, I could get a little longer legs out of my 1st gear. I can presently shift into 6th as soon as 45mph and have it pull cleanly away. I'd like to use my 6th gear more as a "cruising" gear than an "accelerating" gear, if that makes sense.

The reason I'm making such a big deal of this is that I plan on "marrying" either the 285 or 315 size and staying with it. This is because I'm going to buy 5 tires so I can have a full sized spare of the proper size.

The increase in rolling resistance of a 315 over a 265 shouldn't be that big. It's the increase in rotational inertia that I think kills ya. Why? Because we get used to accelerating at a certain speed, not realizing that it takes a bunch more fuel to get a 315 rolling at the same acceleration as a 265 would. So the trick to getting better mpg with 315s is driving slowly and coasting a lot. Coasting lets you re-claim some of the energy you spent spinning up those big meats.

Keep in mind that not only are the 315s MTs 25# heavier PER TIRE compared the Michelin 265s, but that weight is also distributed farther from the hub, giving you a lot higher rotational inertia.

So even with identical overall gearing, the larger 315s will feel more sluggish. Slower acceleration and longer braking distances are part of the deal.

Fishin2Deep4U

Not sure where you are placing the spare.

You probably already know there isn't really enough room under the rig for a 315. A 285 fits with a few kicks.

Now if you are going to a bed or bumper mounted spare, you're golden!

Dave

kwast

haha, you got that right, I was just thinkin' the same thing!!!

ellerman

Go with the 315. That is the size I currently run on my truck with the same trans, gearing and similar power. I can honestly say I average 17 mpg(hand calc'd) non towing, and 10-11 mpg towing. If you already use 1st gear from all stops you won't notice a huge difference. Like the other guys said above you will have to store the 315 spare in the bed because it is to big to fit between the frame. In the near future I'm going to 37" Toyo MT's and will install 4:10's at the same time. Eric

olddodgetruck

i have 315s and love them but my truck is totaly different i have 4.10s and an auto. it sucked on the high way with 265s 2000 rpms at 60 now im at 70 at 2000

Philabuster

I coast a lot when city driving and I did notice a significant difference in rolling resistance with the 315s. I can't coast as far and my truck decelerates about twice as fast as before. Coasting from 50 MPH to 40 MPH in town with worn out 255s and now I drop to 30 MPH from 50 MPH in the same distance. Front tire air pressure is 55 lbs and rear is 40 lbs to get contact patch flat. Truck weighs 7,200 lbs.

Last week, I went wheeling and dropped the tire pressure a bit--40 lbs front and 30 lbs rear. I didn't go lower because I planned to drive home the 15 miles instead of airing back up. I noticed it took much more boost (10 psi boost) to stay at 70 MPH with the tires a bit soft vs the normal tire pressures (2 psi boost).

xtoyz17

I'd go 285 with the m55's. A bit better mileage and probably MUCH better life. Good traction to boot. Extra fuel to get the 315's moving, extra fuel to keep them moving, faster wearing, etc... etc...

Then again I'm sure we could all find plenty of cons to a 285. Personally though, if you're at the stock height I think 285's look great.

xtoyz17

My 285's tow good as well. Can't comment on how stable a 315 would be. Though, you already said you don't really tow.