What factors make Off Road Ability?

[Tweaksta]

Having driven a almost 200,000km in a Subie, and 100,000km in 'real' 4WDs all over Australia, I am trying to identify exactly what makes a Subie so good.

Recently, I had a chance to drive a section of wet and boggy track which I had done regularly in the Subie (with never a problem) in a 2009 Holden Colorado 4x4 3.0 Diesel Ute (same as Isuzu) with chunky Maxxis tyres. I was in 4wd High 1st gear with barely any throttle (about 1400rpm). There was less than 100kg in the tray. Suddenly, I just felt the car sinking into the sodden ground, so I immediately started to steer left to higher ground whilst losing momentum fast. A few seconds later, all four tyres had lost traction and the car was stuck in the slippery clay and mud. 4-low was engaged and we found a pile of rocks which were used to build a bit of a track which then got us out having made a mess of everything within 10 metres.

A 'proper' 4wd with a transfer case and low range made what was normally a Sunday drive in a Subaru, a frikkin messy recovery job!

So....what is it?

Chassis dynamics?
Lower centre of gravity? Possibly (on a climb does the load become an anchor in a higher vehicle)?
Less kilograms per wheel? Yes - I'd say this is a major factor. Even more specific, kg per square centimetre of tyre contact....discuss.
Approach and departure angles? Yes, and no. If the car has crappy traction then it can't do anything with the incline it has just approached. This 4wd with it's great approach angle simply had no use for it. I'd hate to drive it with a load in the back.
Mechanical ability? Well, it speaks for itself really. If the car has **** dynamics then chucking on a transfer case isn't going to help much. This example shows that Subaru's dynamics and AWD system are good at what they do. So much so, that we would benefit from better approach and departure angles because we can climb those hills. Chuck on some ATs and it works even better.
Clearance? Yes. Clearance is a major contributor. Subies tend to have pretty good clearance with most models over 210mm. Those of us who have lifts do love the extra inch or two or three giving us an even greater range of terrains we can tackle.
Fording depth? Again, this site shows that fording in a Subie ain't a problem.
Durability? This is an interesting one. Diesel 4wd utes are certainly built heavy duty. This thing weighs almost 2 tonnes with only a single cab. Repairs on these things ain't cheap. Yet, there are stories of bent chassis around. My Subie weighs 1400kg, I have done almost 200,000km in 9 years and the most expensive repair was the clutch 2 months ago. Apart from that the only component to wear out has been the radiator.

So what am I getting at? I don't really know.

Perhaps 4wd utes aren't the best dynamically due to weight distribution, the wagons (Prado, Cruiser, Paj, Disco, Defender, FJ & FJ Cruiser, Patrol) seem to be better.

I guess I am saying that I like Subies. With an extra few inches of height, and some good rubber they do damn well. The ute has now masticated the section of track that the Subie never dug up......'nuff said.

[Kevin]

"Horses for courses" as they say. Yes, the Subie is light, agile, has a good drive system and has good clearance so for most offroading it is excellent. And, yes, utes are built heavy and can carry heavy loads (which is why I have one) but they will sink a lot faster! When fully loaded the weight distribution in my ute is really good - how do I know this; well, when it's airborne it lands on all four wheels at the same time! (and it has been in the air a lot!) Then again, my ute is just like a big Subie when it runs in 4WD High which the same as AWD i.e. open diffs. But...on really steep sections of track and/or steep rock steps, 4WD, locked on the ute will take you where no Subie dares to venture.

A bent chassis on utes is usually the result of stupidity e.g. towing across the Simpson Desert when overloaded and dragging a trailer on the back. You crest a dune at speed and bingo, bent!

I decided on a ute over a larger wagon because of load carrying capacity; it is very easy to overload a wagon and I've seen heaps in my travels e.g. the Landcruiser is so heavy in itself that it does not take much extra to exceed GVM.

Yes, the Subie does a great job and I really enjoy my Foz but it could not cope with all the crap I carry on extended trips.

[ateday]

Subarus, especially when slightly modifed, eg lifted and with good tyres, are very versatile and capable of a lot.
If you are prepared to do a bit of road building and take it easy along the way they can be surprising.
However the driver`s skill and particularly experience counts for a lot.

[Scooby2]

Tweaksta it could just be a much wetter year ... Not sure of your location but we sure have noticed the wet this year. My dad remembered a similar season .... In 1954. Ironically it has been too wet for us to dig pipes underground to fill an empty tank... !

Best regards,

[Ratbag]

Gidday Tweak

I agree with most/all the points you have made. No way are our cars as indestructible as (say) my '68 LC, but when it dug in, it dug deep and stuck fast ... . Even my '93 Impreza would skip lightly over many sorts of surfaces with equanimity where my LC would have become hopelessly bogged - or torn up the surface badly in getting out.

One of the things that is commonly overlooked by buyers and manufacturers alike is having all the pipes and damageable bits tucked up out of harm's way.

No matter how well this is done, some parts just cannot help being in harm's way. That goes for all vehicles. With my old LC, those bits included both front and rear diffs, and the transfer case! While on that subject, when on bitumen I always had my front free-wheeling hubs disengaged so it was effectively a 2WD with low range and an open diff at the rear ...

Subies have all the brake and fuel lines protected and/or inside the body shell. Ditto the wiring, brake cables and the like. It all helps!

If you take your Forester for a belly slide, none of this stuff gets ripped off ...

[jf1sf5]

The softness of the suspensions is also what helps our Subies. I have tried various spring rates and hydraulic setups and the softer the better for off road. And because the center of gravity is very low thanks to the overall height and flat four (or six !) engine, its also good on tarmac even without sway bars...

[ateday]

They are just good cars.

[gregjet]

Having just divested myself of my dualcab 2007 RA rodeo 4x4 ( with softened suspension which is why I and my kidneys still are able to talk to each other) shod with Maxxis bighorns and now another Subiexv , I think you missed a very important point re: the Rodeo. The off low revs response of the 3.0 turbo is to put it mildly...er....interesting. Even on the bitumen, if you try to accellerate in the wet the rear tyres will light up like a laser and spin until you take the foot completely off the throttle. They will do the same in the dirt in 4wd. It makes them a bit of a pain to drive in soft or slippery conditions. It is a fuelling problem but I never got mine fixed as I lived in Townsville ( dry tropics) so slippery was a wet season affair only.

[MiddleAgeSubie]

I think that the ultimate factor is value.

At the end of the day, the price one pays for extra off-road capability over that of a reasonably modified Subaru is very steep. The cost is very high and the on-road compromises are severe especially versus the turbo and H6 Subaru models.

Thus to me a Wrangler Rubicon is surely worth it--if one can afford a third vehicle.

A Toyota LC, Prado, etc are worth it, if one needs the extra cargo and tow capacity.

As of now, I have to avoid certain trails that would be doable in a stock Prado (Lexus GX here) but they are not that many as to justify paying A LOT more for worse performance elsewhere. Most of the really hard and all extreme trails are goals in themselves and thus of no interest to me.

Indeed, if we replace one of our Subies with a "true" 4x4 at some point, it will probably be chiefly in order to get more payload and towing capability, with the extra off-road capability (low range and better angles) only as a bonus.

Basically, my opinion overlaps with Kevin's.

[idw]

How much one gives a **** about the body work.