315's on stock gears... RPM's on hwy, your location, spare tire lift, etc.

[nspdx]

Yes, this dead horse has been beaten. I know a lot of you guys run the 315's on stock gears. I have been reading what I can find about it on here, but am having a hard time effectively aggregating the info from so many sources in my head.

I just ordered the 2.5" OME lift. I discussed this on the forum and a few have said I should get the 315's because I'd regret not doing it. I have ordered 285/75r16 tires, but they are on b/o and won't ship for a while anyway.

I'm interested in hearing how you guys that are running or have run 315's on stock gears feel about it. Are you still running them? Do you plan to regear? Would you regear if you could afford it? How long did/have you run them? Is it a DD? What is the crawl ratio like? Do you use the PWR/OD-off buttons? Some, or all the time? Are these buttons effective at correcting the shiftpoints and power curve? Are you happy with it off road? Were you running 285's prior to these? have you changed the speed gear? Did this affect shiftpoints? Are there more speed correction kits available than the gear for 285's from Slee? Will the 2.5" OME kit give me enough clearance? Will I need 30mm spacers? If OME kit is good, is it good off road? Where are you storing your spare? If its underneath, then did you do the mod to lift the carrier? Pix of rigs with this lift and 315's would be nice. Also pix of the spare tire carrier with a 315, lifted or not.

This will be my DD and a family rig. My wife has her maxima and we have an old VW camper bus, but it's not about to see DD use. I need for it to be driveable for both of us.

A few things that are appealing about them to me, is that of course, they look better, and it could smoothe out the bumpy roads in SE Portland. How will the RPM's be effected on The highway? Using PWR/OD-off button may be ok. (are these persistent upon turning vehicle off? Or do you restart theem each time you turn it on?) I'm wondering if the 285's will throw my RPM's into a bad spot on the hwy, where perhaps that would be avoided on 315's with OD-OFF. Is city driving ok with pwr button on? Is handling way worse with 315's than 285's? Is handling on road ok?

Would life be better or worse with 285's or 315's for my DD? Right now my commute is about 20 miles a day, mostly highway. Soon to be mostly surface streets, same distance. My vehicle will be mostly a DD, but will get wheeled.

Don't limit your responses to my situation necessarily, but it would be nice if you would address it. This could be a place to aggregate opinions about this. It's addressed elsewhere, but not comprehensively.

Thanks!

 

[Corbet]

DD, PWR always on, want to re-gear to 4.88 when have $, had 295's before. Building spare tire carrier inside cargo area as I can't afford a bumper yet. No speedo correction for me, I use my NAV speedo if need to.

IMO if you live at sea level you'll probably be happy with stock gears. If you play in the mountains you'll want to re-gear. I'm OK without but as soon as I hook up my trailer I'm pretty much crippled on stock gearing (even was with my 295's for that matter).

Here is a driveway pic of the 315's. Have not wheeled it since removing the 295's in November

 

[arndog123]

Power button is always on both my 80's. It never felt right even w/ stock tires w/ the power button off. I haven't felt the need to regear yet but will when I jump up to 37's. For speedo correction I use a Scangauge in each rig. You'll want to get one of these anyway because it provides engine info like water temp. and engine fault codes. A cheaper alternative is an Ultragauge. I would've bought that brand but they weren't out yet when I got the Scangauge's.

 

[rockrod]

I plan on regearing. The cruiser is a slug with the stock gears and 315s.

 

[spdwaver]

Too many questions to answer, so I will give my experience with both a 33" and 35" tire. Both rigs described below either were or are now daily driven.

When I first purchased my 1991 FJ80 (3F-E engine), it was equipped with 35" tires. Since that was my first 3F-E-powered rig, I thought that the tire size was to blame for the lack of power, so I traded for a set of 33" tires. There was not too much of a notable difference between the two sizes, so I regretted ever trading off the 35s. My advice to anyone debating between a 33"/35" or 285/315 is to consider the larger of the two, if feasible.

Now that truck needed a re-gear, in my opinion. I live in an area with lots of hills, so a re-gear would have been most helpful. The 3F-E did great off road, just not the best city engine when sitting on larger-than-stock tires in my area.

[STRIKE]Good riddance[/STRIKE] R.I.P., 3F-E.

Now that I own a 1993 (with it's 1FZ-FE engine), I would even go larger than my 315s without having the need to re-gear; want - yes, but need - no. The 'ETC' button does not boost the vehicle's engine in any way; it merely allows the transmission to shift at a higher engine RPM.

315s do well on the highway, since the RPMs run slightly lower at cruising speed, and I may have even noticed better gas mileage as a result.

 

[retrofive]

315's, only use the power button when in the mountains. Daily drive around town 1500'-2000'. Only noticed a very slight decrease in ooomph when I went up from 285's. Will regear to 4.88's when I goto 37's. No speedo correction, just use the nav.

 

[Prophecy]

As stated the lower your elevation the less you notice. I am all stock gears. Went to 33's no noticable difference, 35's very little, 37's dont notice really anything, I actually get better gas mileage now with the 37's. I don't seem to gun it as much anymore, I WANT people to see them 37's! lol

Was on 285's for about 2 weeks in between 35's and 37's waiting for my rims to show up. 285's were a little faster from the red lights, but man did I waste alot of gas. I don't plan on regearing anytime soon, if ever. I like the fact of having the truck thinking it's running 55mph when I'm actually doing 65mph. I just let the garmin do it's job and tell me what's going on.

Jeremy

 

[nspdx]

So what size lift are you guys running? Off road is good? What about spare storage? (nice looking rig BTW.)

 

[spdwaver]

So what size lift are you guys running? Off road is good? What about spare storage? (nice looking rig BTW.)

I am running an OME 'Medium' 2.5" lift with 2" spacers in the front (to level it out).

Off road-ability is great, actually.

My spare is currently residing in the garage next to the incomplete spare tire carrier that I need to finish and mount. Otherwise, I have mounted it on the roof rack or stuffed it in the rear cargo area (with the third row seats installed).

 

[Trapper50cal]

I may be in the minority, but I find 315's and no re-gear to be perfectly acceptable in every department. This opinion is probably informed by my previous Cruiser being a stock/desmogged 2F in an fj-60 with 35's and 4.11's...

Now THAT was a dog. Going from Downtown Durango (6512ft.) to Molas Pass (10.9K ft.) was a singular torture of 2nd gear and 3rd gear over-rev that made it feel like that tractor motor was going to shake itself into a pile of unassembled parts. (It wouldn't of course, because it's a Cruiser)

In Contrast, the 1fzfe has a lot more power and a more refined climb in RPM's.

With the power button on and the OD off, the 80 will climb Passes a lot more successfully. (assuming 35's and 4.11's - stock gearing)

On the rocks, I have yet to feel like it was lacking for torque or ability...it may be the case that it relies on the auto slipping more to get it done, IDK.

Low range and a locker and this thing goes over what you point it at. (Just don't forget to engage the CDL, I missed a couple obstacles on that gaff)

My 2cents

 

[UCBerzerkeley]

ill add my 2c.

315, no regear, true sea level. pwr on 24/7.

it's OK around town, sluggish, but acceptable. i would not say i am complaining daily about the lack of power. on the freeway, i have even less of a problem. i cruise easily at 70.

however, on trips when you start getting up in elevation, i keenly notice the sluggishness. passing sucks. for this reason mainly, i plan to regear

 

[nspdx]

I just went and looked at some tires. The ones I liked in my budget were the Kelly Safari's. They look pretty sweet. 315's for $900 (4) and $100 less for the 285's. I am truly on the fence... price isn't an issue, but ill need a place to store the spare. What are you guys doing? I've read that there are skinner tires that are 35"ish, that fit better in the stock carrier. do yall know what they are? If I put them on before the lift, will they fit for road driving? Are your rigs still nice to road trip in? We're thinking of driving to Boise tomorrow and its 7hrs each way. I need to be road trip worthy. Pleasant would be good.

 

[BrotherRob]

I went straight from stock to 315s, never regretted it. Wheels like a banshee and good manners on the road. Power button on all the time, I turn the OD off sometimes on HWY climbs. With the big tires I'm over geared so the biggest impact is taking off from a stop. If anything, highway performance is improved, I can cruise at HWY speeds at 1800 to 2000 RPM.

The spare tire? Strap it down in the back until you can get a carrier. It doesn't fit to well underneath and you risk damaging it on the trail.

 

[coax]

Where are you storing your spare? If its underneath, then did you do the mod to lift the carrier? Pix of rigs with this lift and 315's would be nice. Also pix of the spare tire carrier with a 315, lifted or not.

I think this is the key question. I'm still running 285's but was under the impression that 315's wont fit most of the time. (Probably affected somewhat by tire brand, hitch, how much it rubs on the linkage, etc. Check out https://forum.ih8mud.com/80-series-tech/388501-largest-tire-will-fit-oem-tire-carrier.html)

So if you can't fit the spare in the stock location, that leaves either no spare , spare on a bumper ($$), or spare inside leaving you riding around in a tire shop all day.

Know anyone with 315's that you could test fit and see what mods are required to get it to fit? In the end it really comes down to your usage of the truck, if you are gonna wheel alot then 315's are the way to go. More road duty, and I'd stick with 285's.

 

[LINUS]

I realize I'm a hypocrite since I'm now regeared, but since I think I planted the bug in your other thread here's my experience:

-Bought a stock '97 w/ a 1FZ-FE
-Added 305/70R16 GY MTR's - a quick spin around the block & wished I had lift, I'd have gone 315's right then
-Got lift- 2.5 OME Heavy
-1st set of MTR's now bald - Went to order another set, GY ran out of 315's in old tread pattern as they were just making the transition to the 2nd gen MTR Kevlars, so I could wait ~6-8 weeks & pay full retail for the new style 315's, or take a set of old style in 305/70R16 on closeout at a smoking deal - No brainer, took the old style & saved big $$$
-Did a little towing of a sub-20 ft. boat, and a little utility trailer - going over the pass I was glad I only had 33's at the time
-Added factory locker 3rd members, had them regeared ahead of time to 4.88's
-Also added a 4" lift, just to really let a set of 315's flex out - (315's fit a 2.5" lift, you don't NEED more)
-Dropped it off the lift & drove directly to finally get a set of 315's MTR's - It rev'd like a monkey on the ride there with the 305's & 4.88's

We're both at a relatively low elevation, and I was totally fine with 33's & regretted not having 35's anytime except when towing over the pass (Steven's Pass ~4,000ft?)

I never drove on stock gears & 315's - but I can say with my 4.88's now I wouldn't be surprised if my next set of tires are ~37", depending on if there's a MTR that's a 37" for a 16" rim.

Neither of us have the 3FE, so I'd see the need for those guys to regear for 315's - but if you don't tow anything, especially if it's not towing over a pass - then I would (and will if things go right shortly) have 315's on stock gears. I may be buying a 2nd 80 ('97 LX450) & if I get it, I know it needs tires - I'll get a OME 2.5" lift & a set of 315's. In fact, I was happier with the ride quality of the 2.5" lift, so that's as much as I'll go on the 2nd 80 - but 315's fit fine with that & to me it's a winning combo.

 

[Nay]

I ran stock gears and 35's for 18 months. I live at 7,400 feet.

It sucked on 285's when I bought it. I thought 35's were better because OD Off matched the RPM's at highway speed better than 285's and they wheeled far better.

I regeared to 5.29. It still sucked. I installed a Yellow Box speedo correction - fixing the transmission shift points, particularly with PWR on, I think made as much difference for road driving as regearing. I would in all cases do this first.

I put on 37's. It still sucks, but no worse than 35's. Altitude is a far bigger killer to this engine than diff gearing.

Offroad, 5.29's rock. That is the biggest reason to regear.

Net - I would not stick with 285's because of gearing. Fix the speedo for correct shift points, PWR on, and OD Off as you need it. Plus, if your wife doesn't like it, you'll get gears

 

[LINUS]

, if your wife doesn't like it, you'll get gears

That right there may be the '"golden nugget" to take from this entire thread. Seriously!

 

[Wheelingnoob]

A question with the 315's and stock gears in regards to the auto shifting. What does it trough off? I have read a bit about the yellow box mod but just want to understand what the truck does, it is hunting or shifting to soon?

I to am going to make the stock tire to 315 jump when I have the rest of the HG and PM stuff done just want to know if I need to budget for a yellow box as well.

 

[BrotherRob]

My impression is that with the 315s and the PWR on, you are over geared by one full gear. So no hunting. My brother ran 295s for a few years and his hunted constantly. He hated the smaller tires, I have no complaints with the 315s.

 

[akarilo]

I installed a Yellow Box speedo correction - fixing the transmission shift points, particularly with PWR on, I think made as much difference for road driving as regearing. I would in all cases do this first.

Elaborate on the box Nay. I posted some questions about this mod a while back and seem to have gotten some smart ass responses if I recall; due to ignorance I assume.