Suzuki kizashi vs Subaru

[sheps58]

Can anyone tell me how the Suzuki awd system compares to the Subaru?

[matt]

It depends on the Subaru. Most have fulltime AWD that is quite superior to the Kizashi's FWD-based AWD. The Kizashi's setup is like Haldex (and may even be unbranded Haldex).x

 

Which exact Subaru are you considering? Include the year, model, engine and transmission.

[BAC5.2]

All Subarus post 1996 are full time AWD.

[matt]

By "part time" I meant FWD-based with a clutch to transfer some power to the rear, mostly in a reactive manner. The only way you get differentiation is by slipping or not engaging the clutch. The 4EAT works that way, and I think the new CVT does as well. All other Subaru transmissions are true fulltime AWD with a proper center differential. Avoid the 4EAT and CVT if you care about AWD performance. I've edited my original reply for clarity.

[BAC5.2]

No. Even the old 4EAT was fulltime AWD, and the 4EAT migrated away from the old MPT in various years based on model.

 

The MPT cars defaulted at 90/10 split, and could go 50/50.

The VTD (late 4EAT's, all 5EAT's, and I believe the CVT) default at like 65/35, and shift to 50/50.

 

In any configuration, Subaru AWD is only really rivaled by Quattro.

[matt]

The 5EAT (with VTD) had a 45/55 front-to-rear torque split on the 2005-2009 LGT. I'm not familiar with it on other models but I imagine the split is similar.

 

Sheps58, by most accounts the Kizashi is a nice car, but if you're concerned about AWD performance it won't compare to a Subaru. Also you can't get a manual with AWD in the Kizashi.

[TRSCobra]

Also you can't get a manual with AWD in the Kizashi.

 

Or a powerful engine.

[BAC5.2]

Or a powerful engine.

 

Or not a Suzuki.

[TRSCobra]

Suzuki should stick to motorcycles. American car buyers will tell them that same thing, and I'm sure that within the next few years they'll go the way of the Daiwoo.

[Penguin]

The Suzuki is a far superior automobile to any Subaru ever made.

[TRSCobra]

^^^ Better spread the word while Suzuki dealers are still in business, then!

[halwith]

The Suzuki is a far superior automobile to any Subaru ever made.

 

True story!

[matt]

You all are stereotyping the Kizashi. By all accounts it's a good car, and vastly superior to any Daewoo or past Suzuki. Yes the Kizashi's AWD system is inferior to the better Subaru setups but that's true of almost every non-Subaru. The car itself is nice to look at and sit in, and by most accounts it drives well too.

 

Heck, even its crappy AWD system is no worse than the junk being pushed by Ford, VW, etc in their similar transverse-mount, FWD-based platforms.

[scoobyscoodle]

In any configuration, Subaru AWD is only really rivaled by Quattro.

 

Yes, but only when the Audi's electrical system allows the car to start.

[matt]

In any configuration, Subaru AWD is only really rivaled by Quattro.

 

The Evolution IX and X are the only cars with AWD that rivals the STI's. (Yes despite the Evo's transverse layout.) Only the STI and Evo have three limited slip diffs, or a center diff that's a proper differential with a computer-controlled clutch for lockup.

 

Audi's Quattro-branded AWD systems vary almost as much as Subaru's Symmetrical-branded AWD. Most Audis have open front and rear diffs. Unfortunately so do most recent Subaru models. The previous-gen LGT and WRX were better in that regard. Both are still much better than almost everything else out there. (I'll ignore the different merits of Torsen vs VLSD for the moment.)

 

I actually kinda like BMW's setup in theory. Their setup is basically RWD-based Haldex, but that's 100 times better than the normal FWD-based Haldex. It won't match the better Subaru setups for sheer traction but it makes sense for those who want RWD with some extra traction. Though BMW too uses open front and rear diffs (fail), and the way they route the front driveshaft in the 3 series clearly shows it's an afterthought. They also don't offer sporty suspensions with AWD.

 

Hi, my name is Matt and I'm an AWD geek.

[BAC5.2]

The Evolution IX and X are the only cars with AWD that rivals the STI's. (Yes despite the Evo's transverse layout.) Only the STI and Evo have three limited slip diffs, or a center diff that's a proper differential with a computer-controlled clutch for lockup.

 

Audi's Quattro-branded AWD systems vary almost as much as Subaru's Symmetrical-branded AWD. Most Audis have open front and rear diffs. Unfortunately so do most recent Subaru models. The previous-gen LGT and WRX were better in that regard. Both are still much better than almost everything else out there. (I'll ignore the different merits of Torsen vs VLSD for the moment.)

 

I actually kinda like BMW's setup in theory. Their setup is basically RWD-based Haldex, but that's 100 times better than the normal FWD-based Haldex. It won't match the better Subaru setups for sheer traction but it makes sense for those who want RWD with some extra traction. Though BMW too uses open front and rear diffs (fail), and the way they route the front driveshaft in the 3 series clearly shows it's an afterthought. They also don't offer sporty suspensions with AWD.

 

Hi, my name is Matt and I'm an AWD geek.

 

The EVO's control logic for their AWD is mostly rubbish. As far as I know, you can't actually control any lockup of the center diff, other than choosing "snow", "gravel", or "tarmac".

 

While quattro iterations are varied, it does have a proper center differential (a Torsen unit). Todays traction control systems in their lower-end Quattro models mostly eliminate the need for a mechanical LSD. LSD functions can be handled by the brakes. The faster variants (S models) do have rear LSD's I believe.

 

And you CAN get sport suspension packages with BMW's X-drive. I know because my Father-in-law has the Sport package on his 2012 750i (x-drive). And you can get the sport package on the 335ix.

[matt]

The EVO's control logic for their AWD is mostly rubbish. As far as I know, you can't actually control any lockup of the center diff, other than choosing "snow", "gravel", or "tarmac".

That's more than most cars offer. The Evo has a proper center differential, with a computer-controlled clutch added for lockup (IX and X). Not unlike the STI. The STI's center diff is better for a number of reasons, but the Evo is closer than anything else I'm aware of. The Evo's center diff can certainly provide far more lockup than the Torsen in a longitudinal Audi, and do so more intelligently.

 

While quattro iterations are varied, it does have a proper center differential (a Torsen unit).

Not all quattro use a Torsen. The original used a manual locker in the center, the modern transverse-mount ones (VW platforms) are Haldex junk, the latest RS5, A6, and A7 use a novel gear+clutch setup (purely mechanical), the R8 uses Haldex in reverse (a pretty good setup for a sports car), etc. Audi has used almost as many setups as Subaru over the years.

 

Todays traction control systems in their lower-end Quattro models mostly eliminate the need for a mechanical LSD. LSD functions can be handled by the brakes.

Brake-based software LSD, or eLSD as I've seen it called, is nowhere near as good as a real LSD. And using the brakes to simulate an LSD has inherent downsides that can't be programmed around.

 

The faster variants (S models) do have rear LSD's I believe.

The 2010+ S4 can optionally be had with an active torque vectoring rear LSD, like the one in the Evo X. I believe it can function to limit slip as well. Past S4's had open front and rear diffs. So did the RS4.

 

And you CAN get sport suspension packages with BMW's X-drive. I know because my Father-in-law has the Sport package on his 2012 750i (x-drive). And you can get the sport package on the 335ix.

The 335xi sport package has the exact same suspension as the base 335xi. It's not the same as the 335i sport package. In the 335xi it's basically just trim changes and (admittedly very good) sports seats.

 

The 7-series is a luxo-barge. "Sport" does not belong in the same sentence as "7-series" no matter what suspension it's fitted with.

[BAC5.2]

I didn't realize you had replied.

 

That's more than most cars offer. The Evo has a proper center differential, with a computer-controlled clutch added for lockup (IX and X). Not unlike the STI. The STI's center diff is better for a number of reasons, but the Evo is closer than anything else I'm aware of. The Evo's center diff can certainly provide far more lockup than the Torsen in a longitudinal Audi, and do so more intelligently.

 

I'm not entirely sure what you mean when you say "proper" center differential. Do you mean spider gears, or what? Subaru's didn't use a "proper" center differential in the non-VTD 4EAT, despite the clutch packs.

 

Your interest in the computer-controlled clutch is at odds with your dislike of the eLSD you mention below.

 

The only edge an EVO or STi has (more the STi than the EVO, actually), is the ability to provide lockup with all 4 wheels having zero traction. A Torsen will behave as an open diff in situations like this. This however, can (and is) tuned around by the use of "eLSD's".

 

 

Not all quattro use a Torsen. The original used a manual locker in the center, the modern transverse-mount ones (VW platforms) are Haldex junk, the latest RS5, A6, and A7 use a novel gear+clutch setup (purely mechanical), the R8 uses Haldex in reverse (a pretty good setup for a sports car), etc. Audi has used almost as many setups as Subaru over the years.

 

Quattro HAS evolved over the years, but I was thinking more about the current versions, and not truly considering the inherently poor variants that are clearly not competitive with the Subaru system.

 

I didn't know that about the R8, though. Sounds almost like ATTESA (the variant in the Skylines).

 

Brake-based software LSD, or eLSD as I've seen it called, is nowhere near as good as a real LSD. And using the brakes to simulate an LSD has inherent downsides that can't be programmed around.

 

I don't necessarily think that's true, at least not anymore. Wheel speed encoders are at the point where they can determine variations in wheel speed without tires having to lose traction (that is, they can determine the relative position of the wheel, and correct it, nearly before the tire carcass can deform). The inherent flaws associated with modern "eLSD's" can be applied to electronically controlled center differentials.

 

The 2010+ S4 can optionally be had with an active torque vectoring rear LSD, like the one in the Evo X. I believe it can function to limit slip as well. Past S4's had open front and rear diffs. So did the RS4.

 

I noticed that. It looks like all other variants relied on the eLSD concept.

 

The 335xi sport package has the exact same suspension as the base 335xi. It's not the same as the 335i sport package. In the 335xi it's basically just trim changes and (admittedly very good) sports seats.

 

The 7-series is a luxo-barge. "Sport" does not belong in the same sentence as "7-series" no matter what suspension it's fitted with.

 

When we were looking at the 750, I asked if the 335x could be had with some form of sport suspension option like the non-x could. I was told it could be done via special order. I didn't press the issue. They had a 550xi on the floor with the DDC system, which is essentially a "sport" suspension option as part of the M-Sport kit. Didn't drive one, but I would have really liked to.

 

Driving the Sport suspension 7 back-to-back with the non-sport suspension, and the difference is clear. Luxo-barge or not, you can still get a "sporty" suspension with it. I drove the SNOT out of the car we were test driving, and despite it's enormous curb weight it was MUCH lighter and nimbler than the S63 AMG we'd driven earlier that day.

[matt]

By proper center diff I mean one that always sends torque to both sides and can differentiate while doing so, without relying on the friction of half-engaged clutch packs to do it. In other words I mean gears.

 

The Subaru 4EAT does not have a proper center differential. It's like a longitudinal Haldex setup.

 

All the current eLSD implementations are next to worthless. They are not active at high speeds, they don't provide enough resistance to assist much when powering out of a (dry/wet) corner, they don't provide consistent enough resistance to plow through deep snow, etc. At most they'll help you get moving from a stop in shallow snow/ice where you don't need to use much power (but you need the LSD effect anyways cause you're using the wrong tires). Even then you'd be better off left-foot braking or using the parking brake.

 

Now let's say you had a really well-programmed eLSD, one that works at high speeds and be aggressive above providing resistance, etc. (No production car has such an eLSD that I'm aware of.) It would be vastly inferior to a decent traditional LSD for two reasons:

 

1) The brakes will be wasting a lot more energy as heat than most forms of mechanical LSD.

 

2a) Said heat is going into your brakes! No way you could use such an eLSD on the track. You'd be heating your brakes not only while braking, but while accelerating too! That doesn't really leave any time for cooling on the track.

 

2b) Or consider plowing through deep snow, where you need all your wheels spinning constantly to keep your momentum up. You might arrive at the end of the deep section with glowing rotors and boiled brake fluid.

[matt]

Also don't think the software is the only thing holding back current eLSD implementations. They piggy back off of the brake actuators used by stability control, and I'm guessing they're not up to the kind of fine control needed to smoothly mimic an LSD.

[ehsnils]

The Subaru 4EAT does not have a proper center differential. It's like a longitudinal Haldex setup.

 

There are some 4EAT:s that has the clutch pack and some that has a planetary center diff like the 5EAT. But most has the clutch pack since if I remember right it was somewhere around 2007/2008 that some of them got the diff.

[BAC5.2]

There are some 4EAT:s that has the clutch pack and some that has a planetary center diff like the 5EAT. But most has the clutch pack since if I remember right it was somewhere around 2007/2008 that some of them got the diff.

 

The MPT to VTD changed based on model. The WRX went VTD at it's release, but the Impreza had MPT until 03 or something. The Legacy stopped getting MPT earlier, I think, in 2000. The Forester had MPT until late, around 2005 or 6.

[BAC5.2]

By proper center diff I mean one that always sends torque to both sides and can differentiate while doing so, without relying on the friction of half-engaged clutch packs to do it. In other words I mean gears.

 

DCCD, and whatever they call the EVO setup both rely on slipping clutch packs to vary torque distribution.

 

The Subaru 4EAT does not have a proper center differential. It's like a longitudinal Haldex setup.

 

Only the MPT was like that. VTD, which was available in the 4EAT, did use a planetary gearset supplemented with clutches. It was a configuration similar to DCCD, actually.

 

All the current eLSD implementations are next to worthless. They are not active at high speeds, they don't provide enough resistance to assist much when powering out of a (dry/wet) corner, they don't provide consistent enough resistance to plow through deep snow, etc. At most they'll help you get moving from a stop in shallow snow/ice where you don't need to use much power (but you need the LSD effect anyways cause you're using the wrong tires). Even then you'd be better off left-foot braking or using the parking brake.

 

That rear Torque Vectoring differential is essentially an eLSD, it just doesn't use the rotors to provide the lockup.

 

Left-foot braking and using the parking brake are effectively no different than an eLSD.

 

Now let's say you had a really well-programmed eLSD, one that works at high speeds and be aggressive above providing resistance, etc. (No production car has such an eLSD that I'm aware of.) It would be vastly inferior to a decent traditional LSD for two reasons:

 

1) The brakes will be wasting a lot more energy as heat than most forms of mechanical LSD.

 

2a) Said heat is going into your brakes! No way you could use such an eLSD on the track. You'd be heating your brakes not only while braking, but while accelerating too! That doesn't really leave any time for cooling on the track.

 

2b) Or consider plowing through deep snow, where you need all your wheels spinning constantly to keep your momentum up. You might arrive at the end of the deep section with glowing rotors and boiled brake fluid.

 

I don't necessarily agree, and I do think it boils down to a controls problem more than anything. By controlling every wheels speed, and knowing what the driver inputs are, you can keep very fine control over the attitude of the car.

 

Regarding brake heat, I believe you are blowing over it quite a bit. The amount of braking that needs to be done to replicate an LSD is minimal. We are talking about a slight drag, not a full clamp. Just enough to increase resistance on that side of the car. This is clearly something that could be compensated for in brake system design.

 

The goal of an eLSD, and any LSD, is to keep wheel speeds the same. On slick surfaces, you are going to accomplish just that. All wheels going the same speed. You aren't trying to stop wheelspin. That's what traction control is for.

[matt]

Ah, nice, I did not know that VTD was put in some 4EAT. That's much better than MPT, and also better than the VLSD in the 5MT or Spec.B 6MT. (Not that I'd buy a slushbox for anything, but I'll admit that the 5EAT LGT has the better center diff.)

 

 

Well, I'd love to be proved wrong about eLSD. After all it is an essentially free software addon (in per-car costs) once you have the hardware for stability control, which is mandatory these days. If eLSD ever becomes a fixture in racing I'll be a believer.

 

 

DCCD and the Evo's ACD (Active Center Differential) both have an actual gear-based differential for distributing torque between the front and rear axles. The clutches are purely for lockup. That's very different from, and superior to, Haldex-style setups which make the clutch also perform the duties of a traditional differential.

 

Without question DCCD is more elegant and overall superior to ACD. But ACD remains the closest thing to DCCD on the market, even though implementation-wise they're very different.

[WraithAkaMrak]

FWIW, TTAC used the Kizashi for comparison in a review of the new Impreza. It doesn't delve into differences in AWD systems, but in summary:

If you’re turned on by style and refinement, then you’re much more likely to find love in the Suzuki. The way the new Subaru looks, sounds, and feels recalls old style “penalty box” small cars just a bit too much. But if you’re seeking a chassis that talks to you, and that’s a willing dance partner, then the Impreza delivers.

I'd always assumed the Kizashi was in the Legacy's class, but size-wise, it slots in between the Impreza and Legacy, in most dimensions. Does have an extra 10hp on the Legacy, but also a little extra weight.