285/70/17 or 315/70/17?

So I'm looking to gather some information and ideas, I'll have to wait another 6-12 months for the stock tires to wear out before actually doing anything.

Truck is a 2015 CC 2wd with the Pentastar and 3.21 gears. I've been very pleased with it. I have the stock 265/70/17s now. I had been looking to replace them with 285/70 tires on 17x8.5-9 wheels when the time comes, but lately the idea of 315/70 tires popped into my head.

Two things,
1) I had been concerned enough about the heavier LT rated 285s with the Pentastar, but looking at the 315s they are only about 6 lbs more per tire. Granted, they're taller as well. In general, does anyone have any experience going from a 285 to a 315? What sort of difference does it make? I have my concerns, but I also do primarily highway driving so the 315s might not make as much of a difference versus someone who does a lot of city driving. I know the 285s are only about the height of the stock 20s, so I'm more confident those wouldn't cause too much of a difference. But the 315s would look so nice...

2) if I did make the (potentially boneheaded) decision to put 315s on it, would they fit with a 1.5" coil spacer and a 1.5" body lift?

Any lifted Pentastar owners feel free to chime in, I've searched and probably read every thread on the subject and there just isn't a lot out there.

I stopped reading at pentastar.. So here is some info I can offer.

Every pound matters, 1lb or 20lbs.. It matters.

Good luck.

IMO

Fill them with helium.

And yes, every pound matters. That said a 24 extra pounds for tires isn't going to make a difference; this isn't racing or hyper-miling we're talking about. How much extra weight are you packing around in your center console, glove box, storage areas, bed etc.? 4 gallons of gasoline weighs as much as the extra tire weight you are talking about. Tell the members of your family to lose 6 pounds each, etc... IMO just not worth worrying about.

Speedometer calibration issues and rubbing aside, go for the tire size that has the look you want.

AustinB said:

I stopped reading at pentastar.. So here is some info I can offer.

Every pound matters, 1lb or 20lbs.. It matters.

Good luck.

IMO

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Agreed, every pound matters. But in my experience, going from a P rated tire to an LT rated tire makes more difference than anything. On my previous truck, a Titan, I went from P265/70/18 that were on it to LT275/70/18. The weight difference was about 15 lbs, and even though I could still smoke the tires, I definitely felt the extra bit I needed to put to the accelerator even with a similarly sized tire. So I'm inclined to believe that tire weight matters as much as tire height, and once you cross over to an LT tire you've done the largest portion of the weight increase anyway.

I stopped reading at Titan.



IMO

sbarron said:

Fill them with helium.

And yes, every pound matters. That said a 24 extra pounds for tires isn't going to make a difference; this isn't racing or hyper-miling we're talking about. How much extra weight are you packing around in your center console, glove box, storage areas, bed etc.? 4 gallons of gasoline weighs as much as the extra tire weight you are talking about. Tell the members of your family to lose 6 pounds each, etc... IMO just not worth worrying about.

Speedometer calibration issues and rubbing aside, go for the tire size that has the look you want.

Click to expand...

dead weight in the truck is totally different then increased rotational mass from bigger/heavier tires.

yes, its going to make a big difference. whether or not its something you can live with i cant answer that for you. i have no experience with bigger tires on the v6. im sure the 8 spd is a big help in this deparment though. i will say that on my old 1500 (hemi 6spd ) i went from stock 20's to 295/70/18's and noticed a decrease in power an fuel economy. did it bother me, not particularly. in your situation going from 265/70/17's to 315/17/17's its a huge difference. your also going to need spacers if you plan on running 315's on stock wheels.

either way if you go with 285/70/17 or 315/70/17 i would say try to stick with a d rated tire since they are available in both those sizes.

With the v6 and 3.21s I'd stick with the 285s, but it's your choice. Don't think you'll see 7th or 8th gear much with the 315s.

Jerry1984 said:

With the v6 and 3.21s I'd stick with the 285s, but it's your choice. Don't think you'll see 7th or 8th gear much with the 315s.

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Agreed. In the end I'll probably end up going 285s or possibly 275/70/18 to shed some width and weight for a little extra height. I was more just curious if anyone had any experience running something that big on a Pentastar. Can't be any worse than lots of trucks running 35s on smaller V8s and under over the years I figure.

It can definitely be done, just don't know if it will be as enjoyable.

For an update a long time later, I ordered some Falken Wildpeak AT3Ws in 285/75/17 today (roughly 34x11).

It'll be a couple of weeks before I get them mounted up, but I'll report back when I do...

Still not much out there on Pentastars with bigger tires, so hopefully this can help someone out in the future.


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Finally picked up the new AT3Ws. Haven't installed them yet. Anyone know if the 285/75/17 (approx 34x11.5) will fit temporarily without a level? Level or small BL is in the works just haven't had the time to do it yet.

285/75/17 on factory 17s, stock 1500

Installed some 285/75/17 E rated Falken Wildpeak AT3W's on the factory 17" wheels to replace the factory 265/70 Goodyears. That's a little smaller than a 34x11.5" tire, and these are particularly heavy tires, I think in the neighborhood of 66 lbs apiece. The truck is still completely stock and unleveled, but I've noticed no clearance issues so far. I may still decide to level it in the future.

The truck has a 3.6 Pentastar and 3.21 gears. I do a lot of highway driving so I wasn't overly concerned with power loss, but I was curious how the 3.6 would handle it. In my opinion, the little 3.6 still handles the bigger tires just fine. There's a little less oomph but not enough to impact day to day drivability.

I had trouble finding much information on the net both about running this tire size on a stock Ram and about running a tire over 33" on a Pentastar powered Ram. Hopefully this post will help someone out.

you can go to a 305/70/17 before you need spacers

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Appreciate the info satxwy! I'm running the pentastar also but with 3.55 gears. Looking at those exact tires the other day although I still have quite a bit of miles left on the stock tires (which are 275/60/20) before I make a purchase! Feel better about going a little bigger now!

How are you liking the Falkens?

satxwy said:

Installed some 285/75/17 E rated Falken Wildpeak AT3W's on the factory 17" wheels to replace the factory 265/70 Goodyears. That's a little smaller than a 34x11.5" tire, and these are particularly heavy tires, I think in the neighborhood of 66 lbs apiece. The truck is still completely stock and unleveled, but I've noticed no clearance issues so far. I may still decide to level it in the future.

The truck has a 3.6 Pentastar and 3.21 gears. I do a lot of highway driving so I wasn't overly concerned with power loss, but I was curious how the 3.6 would handle it. In my opinion, the little 3.6 still handles the bigger tires just fine. There's a little less oomph but not enough to impact day to day drivability.

I had trouble finding much information on the net both about running this tire size on a stock Ram and about running a tire over 33" on a Pentastar powered Ram. Hopefully this post will help someone out.

Click to expand...

UnsatFC said:

How are you liking the Falkens?

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200 highway miles on them so far. They seem to ride well and don't have much road noise (they seem quieter than the worn out Goodyears, at least). Their construction seems extremely sturdy and they look pretty mean in person. Nothing bad to say about them at this point.