Heya Robin....
You asked for my views about the two. Well I've owned one and driven both extensivly. I'm just gonna give you a li'll run down on both the models although I may be a bit off on the ALTO's motor as I am not sure which one it is.
The ALTO we get was actually introduced in 1998 as the fifth generation ALTO. Although you may have followed the progress of the ALTO, we kept getting the ALTO/FRONTE introduced in 1988. There were both major and minor revisions through the times but we got it all in the 5th Gen. The suspension all though remained the same in other variants, we see ours with Mcpherson struts up front and and Isolated rear link. Weelbase is 236mm, longer than all the previous models. There's been a variety of models including 4WD & Turbo, but we get the C variant, a retro version.I THINK but could be wrong, we get the 4-cylinder 1061 cc engine with 4 valves per cylinder.Our ALTO i8s 10 cm longer and 2 cm wider than the Japanese version.
As with all our ventures to suit our vehicles to the need of the Pakistani motorists, there are compromises made and sometimes, they're adversly affect an otherwise peppy car. Foremost amongst this ever growing list is the suspension. Our manufacturers just can't get the correct damping. Its plagued Toyota, and now Suzuki seems to be getting infected as well. The suspension spoils the overall feel of the vehicle. The steering communicates no feel, and the body roll is GODAWEFUL. I dunno if you'd agree, but from observations, the brakes seem to harden up after every 25,000 to 30,000kms. The GV spec ALTO and all auzuki's for that matter seem to have endless woes about the factory fitted CNGs.
Like i said, overall, its a nice package. The build quality is nice albeit bland. They've tried to spice up the speedo by painting it all funky, perhaps they overlooked adding some velour to the door trims. The build is compact but does sometimes give you a cramped feel. Thankfull being a newr platform is relativly free of creaks and groans.
I state again that i'm not sure about the motor, but if its the 1061 4cyl, 16V it should be around.
The power to weight ratio is about 64.8bhp/tonne lesser than the Cultus actually.
The Cultus on the other hand did'nt go through as many changes as the ALTO. The Swift/Cultus platform had and in some parts of the world still has a cult following.
We saw the Swift as a 4 door hatch powered by the G10 carby in 1988. The rest is history. I think the car remained in production till 2000 and while we were busy manufacturing the older version, the world moved on ( tell me if that sounds familiar) The Baleno ws based on the same platform. The "cultus" shape was introduced in 1990 and we got the Swift Sedan 4 door version, no the Hatchback. The s-4 platform went out of production in 1995 but Suzuki apparently had plenty of left over refuse to send out way.
Again like the Alto, it was modefied and came with the G10. Also has body roll but less excessive than the ALTO. Overall good economical package. My example startd creaking at thedoor flanges and had to redo them at 40,000kms. Other than that, the front and rear bumpers are a bitch to realign after even a minor collision.
Parts for the cultus are a bit expensive than the ALTO but i'm not sure about that.
The other thing you mentioned about the ALTO being quicker off the mark. The reason is the 4M manual transmission. Suzi Pakistan sticks the 4M into ALL their Five throw cars. The Margalla had it, the Khyber had it, The baleno 1.3/1.6 had it andnow the Cultus & ALTO. The reason it suits the ALTO better than the CULTUS is because the G10 is an oversquare engine with a long stroke (74,, X 77 mm for the Cultus and 68.00mm X 72mm) The slightly shorter stroke helps for quicker responce.
The second question you asked is about the fuel consumption. I really don't have any facts regarding that but i can tell you this that the G10 is better engine in the sense that it actually a SOHC as compared to the OHV in the ALTO making it quiter and economical.
The stats for the cars are as follows.
CULTUS:(G10 Crburettor)
Displacement: 993 cc
Compression Ratio: 9.50:1
Max output: 60.8 PS (60.0 bhp) (44.7 kW)
@5500 rpm
Max Torquw: 83.0 Nm (61 lbft) (8.5 kgm)
@3500 rpm
Power to weight ratio: 96.77 bhp/ton
ALTO:
Displacement: 1061cc
Compression ratio: 10.1:1
Max output: 61.8 PS (61.0 bhp) (45.5kW)
@6000 rpm
Max. torque: 85.0 Nm (63 lbft) (8.7 kgm)
@3200 rpm
Hope that helps...