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The other negative I hear with Run-flats is their ride quality suffers from the extremely stiff sidewalls.

And you have the same restriction as you do with a donut spare - limited range. Not great on a long trip car.
 

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The Tribeca has taken so much fire for its 3rd row, which is an unwarranted critics' obsession as not everyone needs to haul a boatload of adults around, and for its mpg, which is really not that bad for the 2006-13 time-frame. Its only truly annoying feature is indeed the range, especially in the vast open spaces of the West.
 

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Could have lost the spare for a larger tank, it's the new trend.
Interesting comment. If I remember, correctly about 3 or 4 years ago, I got an email from Subaru of America, asking to do a online survey for a 7 passenger vehicle. Two of the question I remembered from the survey (on a scale of 1-5):

1. Run-Flat tires. - I put a 3, on the fence with these.
2. A larger fuel tank. - I put a 5 and I even commented on it in the open comment section!

At the time I was guessing Subaru considered another refresh/upgrade for the Tribeca, involving removing the spare and adding a larger tank. The exciting part was the question about the larger fuel tank mentioned pushing the range up to 400 miles! Maybe they could have fitted the 18.5 gallon tank from the Legacy/Outback into the Tribeca.
 

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While I do not plan any further vehicle purchases this decade, I cannot wait to see the new 7 pax. I am very curious how they will address the various things for which the Tribeca was criticized. My fear, however, is that it may be a more minivan-ish rather than SUV-ish vehicle.
 

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With tires, simply taking the time to insure that they are at proper pressures will help with more real-world mileage gains than switching to a particular "fuel economizer" tire, whose break-even point can well be years down the line - and payout will be delayed/negated if pressures are left unchecked yet again.
 

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Discussion Starter #27
I checked the Lexus RX 350 weight and it's basically the same as the Tribeca but I've never heard complaints about Lexus fuel economy (not the same as driving range, that's tank size obviously). I do like the interior styling of the 'Beca and our Subaru mechanic is an hour away compared to 2 1/4 hrs for Lexus. Part of the joys of living in rural Nova Scotia :mad:
If a low mileage one with a tan interior shows up sometime we'll see . . .
 

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I think 255 wide tires are one big hit in MPG, going to switch to 235 and see if it gets a bit better.
I would not do that. You would loose grip, made your car less 'safe'. Also I do not think it is a big hit in MPG.
 

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also lowering the car generally helps, so do flat skidplates that create smoother underbody.
Yes, for HW driving, would not do a thing for city/lower speed driving. Too much expense for little gain in MPG I think.
 

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I would not do that. You would loose grip, made your car less 'safe'. Also I do not think it is a big hit in MPG.
grip depends on the contact patch and yes there is more lateral grip on wider tires, however it also depends on the tire compound, tread design and road conditions.
Wider tires are only good in dry weather and for stopping if they are any good, when wet you have a much bigger chance of hydroplaning, in icy conditions you have less pressure as the weight is distributed across larger area.

On my outback that I owned for 7 years I swapped about 14-16 sets of wheels and tires, and I believe on my experience and for my style of driving it will be better to go narrower on the Tribeca. Most other SUVs in this criteria use 225-235 wide tire, only luxury/sport ones go this wide.

As far as skid plates yes it is only beneficial fuel wise on the highway, I tend to drive at higher speeds so every little bit helps. But in city it helps with giant protruding manholes, dips and other weird road hazards you get in the city.
 

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The Tribeca has taken so much fire for its 3rd row, which is an unwarranted critics' obsession as not everyone needs to haul a boatload of adults around, and for its mpg, which is really not that bad for the 2006-13 time-frame. Its only truly annoying feature is indeed the range, especially in the vast open spaces of the West.

Agreed... if someone wants a true 7-seater, they can go buy a conversion van. But not everyone wants to drive a monstrosity on the road, regardless of gas mileage. The Tribeca did an excellent job of "crossing-over" the 5- and 7-seat SUV markets. A lot of us who drive 7-seaters aren't hauling around 7 adults... we're hauling 1 adult and 3-4 kids, and that's where the Tribeca excels.

What killed the Tribeca was simply poor luck in launch timing. In its third model year, the economy tanked, gas prices skyrocketed, and SUV sales across the spectrum of mfg's fell off the cliff. The Tribeca didn't catch on during the "early adopter" stage to garner awareness and a following amongst a majority. There simply weren't enough early adopters as hardly anyone was buying SUVs during the recession.

If the Tribeca were launched today, it would most likely endure longer than 8 model years.
 

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The other negative I hear with Run-flats is their ride quality suffers from the extremely stiff sidewalls.

And you have the same restriction as you do with a donut spare - limited range. Not great on a long trip car.
Another negative I read about is that run-flats generally cannot be repaired, so if you get a flat, you are buying a new (expensive) tire. This seems to be confirmed by the Bridgestone website (random selection), which states

It depends on how far and at what speed the car was driven after the puncture was sustained. Repair is possible only if deemed so by the tire sales store. Preconditions include a puncture of less than 6mm for both side-reinforced type and support-ring type Run-Flat Technology tires, plus minimal damage to the support ring in case of the latter. However, it is strongly recommended that the tire is replaced as its durability will have been weakened after being repaired.
 

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Tdelker Thanks for the link. Very interesting. Off topic but does anyone remember GM's space saver spare.
 

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Actually, I have been wondering about wider tires and fuel economy. Someone recently reported switching an OB to something like 255 (!) w/o a loss in mpg. The fact is that the Tribeca is substantially heavier than the H6 OB while getting an mpg which is not dramatically different in the city though noticeably worse on the highway. The very worst I have done on the H6 was over 2,200 miles, to the San Juan mountains and back, 150+ miles of 4wd HC roads all the way up to 12,950ft, larger than stock AT tires, roof carrier over half of those 2,200 miles (to campground and back) = 22.7 indicated mpg. Generally, I get anywhere between 24.5 to 28 indicated mpg out of town. By contrast, an equally loaded Tribeca with the same roof carrier could not brake 22 mpg under the best of circumstances.

Still, it seems to me that the weight difference is the critical factor with tire width a minor one, if that.

I am now waiting for a promotion on the Bridgestone Ecopia for the Tribeca with the YK 580 being the alternate (currently we run YK 520). The OB handles off-pavement duties and all I want on the Beca is a low-noise, comfortable, long-lasting, low rolling resistance tire.
 

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Wider tires are only good in dry weather and for stopping if they are any good, when wet you have a much bigger chance of hydroplaning, in icy conditions you have less pressure as the weight is distributed across larger area.
Dry, yes - more contact patch = more grip.

Wet, yes - wider = harder to resist hydroplaning

Icy? Surprise - no, wider is actually better:

From last winter, Continental came out with that shocker of a recommendation, going against conventional wisdom that in the winter, narrower tires are better - instead, they declared that there's no reason to go narrower at all, and that staying stock width or wider actually would result in better overall gains.

This, not surprisingly, upset some in the community who are staunch traditionalists, while it set others to thinking that maybe it has to do more with what's under the top layer that the narrower tire is cutting through.

It was all speculation until just a little while ago -

From my SubaruForester.org post on winter tires, with SubLGT's quote taken from his post on NASIOC.

The Finnish enthusiast magazine Tuulilasi has an interesting comparison in this years winter tire testing. A member of a Finnish BMW club posted the test results here:
Rengastestien tuloksia ja linkit keskustelua renkaista topiceihin - Page 4 - BTCF Forum

Tuulilasi tested two different sizes of the studless Nokian R2: 205/55R16 and 225/45R17. It's been 6 or 7 years since I have last seen a test of this type.

The advice you often read and hear about winter tires is to choose a size that is skinnier and taller. The data from Tuulilasi helps us see what we gain, or lose, by going to a skinnier, taller winter tire.

The results:

A. In acceleration on ice, the 205 tire was 1.2 sec slower to 20 km/hr than the 225 tire (15.5% slower).

B. In ice braking (20 km/hr down to 5 km/hr) the 205 tire required an additional distance of 2.1 meters (9.9% longer) compared to the 225 tire.

C. On the ice handling course, the lap time for the 205 tire was 3.7 sec longer than for the 225 tire (3.6% longer lap time).

D. In acceleration on snow, the 205 tire was 0.03 sec faster to 20 km/hr than the 225 tire (2.9% faster).

E. In snow braking (20 km/hr down to 5 km/hr) the 205 tire stopped 0.24 meters shorter than the 225 tire (6% shorter).

F. On the snow handling course, the lap time for the 205 tire was 0.9 sec shorter than for the 225 tire (2% shorter lap time).

G. In the slush planing test ( 2 tires on slush), the 205 tire can go 1.1 km/hr faster than the 225 tire before the onset of slush-planing (3.5% faster).

H. In wet braking (from 100 km/hr to 0 km/hr) the 205 tire stops 2.7m shorter than the 225 tire (3.8% shorter).

Conclusions: In terms of percentage, you can lose more in ice traction than you gain in snow traction, by going to a skinnier, taller tire. A difference in tread width of only 20mm had a bigger effect on ice traction than I was expecting to see. As expected, the skinnier tire is better at resisting slush-planing. The skinnier tire is substantially better at wet braking (I assume the test track was wet with standing water, and not just damp).
To-date, this is, AFAIK, the first true test of the skinny/wide debate.

Note that it's a two-size jump in width: 205 to 225.

It looks like there's definitely things to be gained and lost on both sides of the equation, and that neither is a clear winner; as-usual, I think that the absolute numbers tell as interesting a tale as the percentages.

Finishing his post, SubLGT had the following:

Other observations: Among the 10 tires tested, the single performance winter (Conti TS850) scored #1 in resistance to slush planing, consistent with what I have seen on other tests over the last 5 years: performance winters are better performers in slush than studded or studless winter tires. Unsurprisingly, the XIce Xi3 scored near the bottom in the slush test, coming in ninth place.
And later, also on SubaruForester.org, I made the following reply to Rumrunner -

TSiWRX said:
my OEM size is 225 55 17
my snows are 205 65 16

wifey had an old toyota tercel with pencil thin tires that did great in the snow cuz they didn't float. when the wheels were turned they dug down to the pavement and turned the car. wider would just float on top of the slush and do nothing. I think it's common knowledge to downsize for snows. of course you will have great improvement going from oem tires to snows even if you stick with the oem size
It's complicated:

http://www.subaruforester.org/vbulletin/4172146-post157.html

Of-course, the temptation is always to bring up rally cars :icon_razz: - what we're looking at, there, however, are tires quipped with spikes that are themselves designed to bite into ice or hardpack underneath the overlayer of powder.

Yes, a narrower tire "cuts-through" better, both as conventional wisdom as well as the test data would suggest - but if what's underneath does not provide the tire with sufficient traction, then it's a no-gain situation. To wit: how many are willing to run significantly narrower and taller studded tires and sacrifice not only steering feedback but also NVH and clear-roads performance (i.e. safety), for pure gains in terms of wintry conditions (that pencil-thin fitment may have worked great on your wife's old econobox, with its weight and weight distribution - but what about a significantly more massive vehicle?)? And even suppose the particular driver lives where wintry weather truly dominates - that there's *always* white on the roadways - is that actually powder (and thus favorable to a narrower tire), or is it more of a persistent hardpack with icy spots, where a wider friction ("Studless Ice & Snow") tire may actually work significantly better than a narrower studded tire (here, because of the persistent whitewash of the roadways, it's most likely that temperatures would also favor the former)?

The data points to a two-size jump (as with your fitment, Rumrunner) as being perhaps the first time that we can really - as drivers in the tremendously variable conditions seen in real-world driving would present - see an actual performance difference in the narrow-versus-wide context. Yet, there's great trepidation with drivers looking to select between a 205-versus-215 or a 215-versus-225 fitment: a degree of worry which the data suggest is not warranted. Rather, it's more important that we realize that this difference is secondary to first having chosen the proper sub-genre of winter tires for-conditions, that there's great differences between an "All Weather" tire versus a "Performance Winter" versus a "Studless Ice & Snow," and that shoppers should not simply look at or hear the word "Blizzak" from their chosen retailer, and just assume that it's all the same.

Currently, the leading misconceptions are:

(1) Even the worst winter tires will be better than the best All-Seasons in wintry conditions - we've seen that this is blatant marketing lie as test-data suggests that, quite frankly, the worst winter tires perform worse than top-tier All-Seasons in wintry conditions, and that this gap stretches even wider when there is no wintry precipitation on the roadways.

(2) "45-deg. F. and switch" - again, we have quantified data, both from reliable test sources as well as from same-brand-multiple-genre comparisons to suggest that the actual temperature range dips significantly below this point, and that, what's more, it's actually the presence/absence of wintry precipitation on the roadway surfaces that makes the biggest difference in terms of when to switch-over.

(3) That a narrower fitment is outright better for winter applications - here, the latest test data suggest that one needs to dissect more carefully exactly what one desires from the tire in terms of performance characteristics, and that a two-size change in width, provided that we keep the same tire, may be the first time that we can see real-world differences.

--

Sorry for the slight side-track. :eek: Winter tires are kinda a passion of mine. :)

IMHO, anything tire-related for a real-world vehicle such as the Tribeca should first be rooted in proper tire maintenance. Getting out there and making sure that your tire pressures are optimized (the easiest way to look at this is in terms of tire wear) is first-line, and most experts quote this rather shocking figure: that under-inflated tires lowers gas mileage by 0.4 percent for every one pound of drop in pressure of all four tires (down by 10 psi?... you're losing four percent in fuel economy). If you're the type who routinely sees that TPMS warning once a year, you can probably do better on this maintenance task. ;)

And make sure that your break-even point for a tire-purchase that's ostensibly made for fuel economy reasons will actually pay out over the anticipated course of your vehicle ownership.
 

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TSiWRX,

That is another great post on the subject.

As for the so-called fuel efficient tires, they are also those with good noise and comfort levels. Of all tires in the 130-180 range, the YK 580 and the Bridgestone Ecopia just seem good choices. Of course, we live in Phoenix: an actual rain is an event and snow is an optional drive to the north.
 

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TSiWRX,

That is another great post on the subject.
Thanks for the compliment. :eek::)

As for the so-called fuel efficient tires, they are also those with good noise and comfort levels.
^ And that's tremendously important as well, with a family/cruiser vehicle like the Tribeca.

As my friend who drives a lot reports of his Tesla, it's much more relaxing to drive/travel long distances in a vehicle which offers good ride quality as well as overall serenity.
 

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I have had mine since May 2013. I have put about 18,100 km on it since and for what it's worth, averaged 14.6L/100km or 16.2 MPG. My range therefore is approx. 440 km or 274 miles. Best was 10.7L/100km, worst was 21.6L/100km All highway vs all city I suppose. Sometimes, I can't believe that's the same car. I am in Toronto.
 
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