Max tire size - Rancho & Spacers

[Rooikat]

Hey guys, long time lurker, first time poster.

So, I did a fair amount of searching and couldn't find anyone with my direct setup for comparison.

Yes, a first time poster that did a decent attempt at searching!

Anyway, I have a 2004 XLT V6 that I just put Rancho Quicklifts on, which should give me an intial lift of 1.75" in the front and 1.25" in the back. I would've liked more, ups, but didn't want to have to stretch it to the limit.

I also got 1.25" wheel spacers all around. Again, wanted to push the tire down and out from the body, but without straining the stock suspension too much.

My question is, what are my options for tire sizes? I'd like to be able to safely go lock to lock and/or hit a pothole without rubbing... so not the absolute limit where I can't hit a speed bump without hitting my fender too, but just a hair back... or tell me what that limit is so I can dial it down!

I'm on factory 16"s, but am considering a move to a 17" as well.

If it counts anything for help, I joined Elite Explorers to support the forum & hopefully buy my way to some good advice.

 

[extra-medium]

I have quicklifts and run 267/75/16's. I only get a split second of rub when I am at full lock when I go from a stop in reverse. You also don't want to go much more than that because the v6 can't push that big of a tire that well down the highway. You get a lot more rolling resistance, which in turn puts more stress on the axles, weak differentials, and weak transmission.

 

[Rooikat]

Awesome, exactly what I was looking for.

So with the spacer & same size tire as you, I should be alright on rub at lock then?

I hadn't even considered the weight... going to have to give some thought to that.

 

[extra-medium]

You should be fine. I think some people have gone to a 285, but I wouldn't try it unless I had the V8. I am not sure what the stock 245/70/16 on the wheel weighs, but I know my tires are 50 lbs a piece, plus the wheel, so I am assuming it's lose to 65-70 lbs for each wheel/tire.

 

[Rooikat]

Yeah, I was going to scope out the trade off between 17" vs 16" in terms of how much rubber you end up carrying... but even in all the threads, there was so much focus on clearance or alignment that I must have overlooked the fact that large wheels simply weigh more.

 

[drdoom]

Consider your gearing too.

 

[extra-medium]

So I just got back from my first road trip with the 265's. I have the 4.0 v-6, 265/75/16's and 3.55 axle AWD Mountaineer. I averaged about 14 mpg on the highway. Any sort of headwind or the slightest uphill my trans would downshift into 4th gear and stay there. I would have to tap the gas or push the overdrive button off and back on to get it to shift back into 5th gear once I crested the hill or got onto flat ground. I like the look of the tires, but they definitely put more strain on the motor.

 

[mcclain61]

How many miles is on your engine?

I have the same size tire except Explorer not mountaineer (idk if there is a weight difference)

I normally get 14-16 mpg no problems with shifting into od

140k miles and clean transmission fluid/filter

 

[extra-medium]

I have almost 160k. I have a somewhat fresh engine after I had to replace one head when I did my timing chains. The bottom end is all original. Trans has about 100k on it. The only difference I see is I have full time AWD, explorer just has auto 4x4. I have thought about taking my front drive shaft out for the summer, just wondering how much that would help.

 

[mcclain61]

Don't remove the front driveshaft it needs it for park to work otherwise it can roll,

I don't think it will make any difference in fuel mileage other than removing some weight.

Only thing I could think of would be the servo bore leaking,

Where about dare you driving?

I'm in TN around Bristol

 

[extra-medium]

I have heard differing opinions in removing the front drive shaft. The transmission is where the parking gear is so I don't see why it would roll while in park if the front shaft is taken out since the rear driveshaft is still in place, and the transfer case is always in gear since it is non-shiftable. Taking it out should help fuel economy because there isn't the strain on the drive train sending power to the front.

I'm not sure where all it could be leaking, but there are no puddles under it at all. There are no warning lights on, and everything shifts fine in the trans.

On my trip I took, I was driving on I-64 and I-95, and I-40, so all interstate with speeds between 55-70. With my old set of 245/75 tires I would get 18-20 mpg on the highway. It used a whole tank down, and a whole tank back, a total of 330 miles each way.

 

[mcclain61]

The transfer case acts as a differential .

You could use the parking break and that would work.

Give it a shot and document it for a few tanks of gas but I don't think you see any real gains

http://www.explorerforum.com/forums/index.php?threads/servo-bore-fix-5r55w.313199/

 

[jonboyb]

Extra-Medium.....do you have a pic of your Mountaineer with Quick-Lifts and 265's? Building a "Pre-Runner" 2wd for son's first and that's the combo I'm looking at, but heard various heights associated with the QL's. Thanks.

 

[extra-medium]

These are all with the 265's. The bottom picture has a comparison with the 265's with quicklifts on top and 245's without quicklifts on bottom

 

[extra-medium]

I can measure the wheel arch height and ground clearance at the running boards next week when I get home, just to give you an idea of the size. I wish I had stock measurements at the wheel arch, but I don't.

 

[jonboyb]

Thanks for the pics! My Mountaineer looks to have way more open fender with stock 245/70's than your bottom pic??? Let me host a pic if I have one.

 

[jonboyb]

Only one I have....hard to see. Fender wells are big gaping holes.....the tires look way too small, but they are 245/70's. Especially the rear.

 

[extra-medium]

Here is a pic the day I got it, when it had the 245/70 Goodyear Assurance Triple Tread tires. You can see the gap in the wheel arches, and it had that nasty rear rake. Those tires only lasted another couple months until midway through that winter when I got the Cooper Discoverer AT3's in the pic with the mud and I went up to a 245/75. This go around I opted for the 265/75 Cooper RTX and am happy for the most part except fuel mileage, but there has to be a trade off somewhere.

 

[jonboyb]

To keep weight down I ordered 265/70/16 Duratracs instead of the 265/75's. Kept me in a 40 lb standard load tire instead of a 60 lb LT Hopefully they still look good.

 

[jonboyb]

Yeah.....the 265/70/16 Duratracs are PLENTY big without lift....lol. No rubbing even all flexed out though. Look like QLs in my future.