Fuel economy and iAWD - let the fun begin!

[Firefly]

I can feel the difference in curves. I can actually accelerate through curves with a feeling of confidence in AWD, more so than in FWD. On dry roads, AWD gives a more balanced and connected feeling. Not a dramatic difference but I do feel it.

[murcod]

If there was more power, or a manual trans, with the AWD it would make the difference night and day!

I had a small 4WD turbo hatchback in the early 1990's that had a fair bit of work done to it. To dyno it, the tailshaft could be removed and a lever pulled out on the transmission- it could then be dynoed in 2WD (FWD). I drove it for a few days on the road in 2WD/FWD and it was an uncontrollable death trap! It would change lanes at 80km/h simply by flooring it in a low gear (from torque steer) and wheelspin in first and second gear was explosive. With it in 4WD it was very placid (comparatively speaking!) to drive- no torque steer and impossible to spin the wheels from the standing start due to the immense grip. It was hard to believe it was the same vehicle....

Sadly, the Kizashi doesn't need AWD to tame immense power.

[WESHOOT2]

In no particular order:

1) MY AWD Kizashi actually does get (ever-so-slightly) better MPG with its AWD system disengaged.
Except I bought it for its sophisticated torque-distributing AWD system (a system unlike most, not demanding wheel slippage, able to proportion torque appropriately ).

2) Subaru uses two systems: a vicious-coupled center differential and a 50-50 torque split under normal driving (yet if one end 'slips', the fluid expansion from heat acts on a center clutch-pack for distribution) only for the manual-transmission models; an electronically controlled clutch-pack that senses wheel-speed difference and proportions torque from its 'normal' 90%-front/10%-rear operation for the 'automatics'.

3) I notice a significant difference between AWD and FWD modes when pushing; the AWD mode seems to have heavier, more-weighted steering feel, while the FWD mode makes the car feel lighter, more frisky, with a lighter feel through the steering.
The AWD-mode handling feels more planted, more progressive, less able to be deflected.
On unpaved surfaces it becomes a night-vs-day choice, with rear and 4-wheel drifting possible in AWD mode. FWD mode renders the car exactly that.
(Test for yourself, fellow AWD owners: Race your car both up and down the same mountain, 'cause AWD means squat on a heavy downhill corner. Ay?)

4) I get better mileage in FWD mode in the rain or light snow, but I don't drive in that mode

5) Today I will pass 90,700 miles on my 2011 AWD S.

[WESHOOT2]

AND.....I ain't even mentioned what happens when I disable the VSC......




something in a "yee-haw", perhaps?

[x-90 kid]

the main difference that i see between 2wd and awd in my 2010 kizashi is that i get more grip but i can power slide it in a more controllable way. I still get about 30 mpg with the awd on.

[murcod]

http://www.familycar.com.au/app/article ... izashi-awd <- if all of that is true then there should be a huge difference!

[rp2s]

Actually, the AWD systems used in the Kizashi and SX4 are very different. Engaging iAWD in the Kizashi is the same as "locking" the iAWD in a SX4 and you could only do that if you were on snow, mud or sand. Which is why the SX4 would switch back to "auto iAWD" as your speed reached 38mph. The SX4 used a three mode system, the Kizashi is four mode, hence "all-season, all-surface" functionality. When you add in the VDC (vehicle dynamics control) in the Kizashi, there is no comparing the two systems, as the Kizashi can transfer power front to rear and side to side depending on power, braking, steering input and chassis dynamics. As a result, the Kizashi will suffer a bit in mpg's when its iAWD system is engaged, as it's always sending at least 30% torque to the rear wheels.

[Knightstruth]

Actually, the AWD systems used in the Kizashi and SX4 are very different. Engaging iAWD in the Kizashi is the same as "locking" the iAWD in a SX4 and you could only do that if you were on snow, mud or sand. Which is why the SX4 would switch back to "auto iAWD" as your speed reached 38mph. The SX4 used a three mode system, the Kizashi is four mode, hence "all-season, all-surface" functionality. When you add in the VDC (vehicle dynamics control) in the Kizashi, there is no comparing the two systems, as the Kizashi can transfer power front to rear and side to side depending on power, braking, steering input and chassis dynamics. As a result, the Kizashi will suffer a bit in mpg's when its iAWD system is engaged, as it's always sending at least 30% torque to the rear wheels.

My understanding with the awd engaged it only activates when it detects wheel spin otherwise it is the same as fwd.
I can say that the legacy had two different awd systems. For the 4 cylinder it had a 60-40 split and the straight 6 was 45-55. The bmw I had was 38-62 under normal circumstances.
In other words I had to get use to a pure front wheel drive car again because the other ones I had were always on awd.

[LPSISRL]

Actually, the AWD systems used in the Kizashi and SX4 are very different. Engaging iAWD in the Kizashi is the same as "locking" the iAWD in a SX4 and you could only do that if you were on snow, mud or sand. Which is why the SX4 would switch back to "auto iAWD" as your speed reached 38mph. The SX4 used a three mode system, the Kizashi is four mode, hence "all-season, all-surface" functionality. When you add in the VDC (vehicle dynamics control) in the Kizashi, there is no comparing the two systems, as the Kizashi can transfer power front to rear and side to side depending on power, braking, steering input and chassis dynamics. As a result, the Kizashi will suffer a bit in mpg's when its iAWD system is engaged, as it's always sending at least 30% torque to the rear wheels.

I assumed that since both the SX4 and the Kizashi had a system called iAWD by Suzuki they were the same system. I can't imaging that Suzuki would engineer a whole new system for one product? I do know that when you put the SX4 in lock mode, it sends 50% to the rear until you reach 30 something miles per hour and then it goes back into iAWD. I didn't read all the stuff in the owner's manual regarding iAWD because 1) I thought it was the same as the SX4 which I already owned 2) My SLS is FWD so I'm not really concerned about it.

[murcod]

The important bits from that previous link - in case that page is ever taken down:

Drawing on more than 40 years of engineering expertise, Suzuki has developed an active all-wheel drive system designed to maximise the driving experience.

“Kizashi Sport AWD actually anticipates oversteer or understeer and can split drive to either the front or rear wheels to provide maximum driving enjoyment

“This ‘sixth sense’ makes the Kizashi Sport AWD Suzuki’s ultimate expression of driving dynamics.

“For example, when you accelerate from rest, the system detects the extra throttle input and automatically sends drive to the rear wheels to ensure a smooth, safe take-off.”

Devers said Kizashi Sport AWD inspired greater driver confidence by enabling optimum take-off, acceleration and cornering.

He explained a key element of the new i-AWD system was feedforward control, which adjusts the proportion of engine torque sent to the rear wheels according to road conditions, vehicle dynamic conditions and driver input.

The system was created by an engineering team drawing on more than 40 years’ expertise in all-wheel and four-wheel drive. It has helped them create an all-wheel drive system for the road; a system representing a new era in driving enjoyment.

“Most soft roaders and all-wheel drive systems employ a reactive system that engages all four wheels only after detecting a loss of traction.

“With the Kizashi Sport AWD, the new active handling works in partnership with ESP to ensure optimum handling levels. We call it synergetic vehicle dynamics control.”

By constantly monitoring inputs from all the ESP sensors – wheel, steering wheel, yaw and lateral g – the system can anticipate when to increase or decrease torque to the front or rear wheels and even provides counter-steering assistance.

The technology adds an extra level of driving enjoyment, while working in tandem with ESP to ensure occupant safety levels are never compromised.

In normal driving, the system is constantly monitoring data sent from all the sensors. In a standard car, excessive understeer would be countered by reducing torque to the front wheels and braking the inside front wheel to assist turn-in.

The Sport AWD uses the same data but, if the ESP threshold has not been crossed, the logic helps enhance the driving experience.

By decreasing torque to the front wheels and simultaneously increasing torque to the rear wheels, it limits understeer, helps the car turn safely and contributes to the driving experience.

In an oversteer situation, the car reduces torque to the rear wheels, increases torque to the front wheels and provides counter steering assistance.

By actively reducing excessive oversteer or understeer, it encourages a more neutral handling characteristic.

“The system was developed by Suzuki engineers with a priority on driving feel, not just its operating logic.

“Kizashi was always designed to be a driver’s car, and the Kizashi Sport AWD represents the definitive example of that philosophy.”

Devers said while the system would reward enthusiast drivers, the impressive safety systems inherent in every Kizashi ensured maximum safety for all occupants was never compromised.

i-AWD system

Power to the rear wheels is delivered via the i-AWD controller, which constantly monitors driver input and vehicle dynamic conditions to deliver the most efficient division of power.

The key delivery component is an electronically controlled wet-type multi-plate clutch coupling, in which the degree of magnetic clutch action is modulated to provide optimum traction.

The coupling is regulated with an electrical current alternating between the two and all-wheel drive modes, based on data supplied by the array of sensors including wheel, steering wheel, yaw and lateral G.

In a first for Suzuki, the transfer case features a force-fed internal lubrication system to ensure improved durability.

The AWD system can be engaged on the fly by pressing the dash-mounted switch.