4th gen ludes came in these trims
Type S (F22 135 hp)
Type Si (H23 160 hp)
VTEC (190 - 195 hp H22)
4WS (H23 with 4 wheel steering)

5th gen ludes came in these trims
Base (H22 195 hp)
Type Sh (H22 195 hp with ATS or something like that....traction control...also it had a different rear deck and trim options)

 

and Yes SR is canada

SR is equivilant to the Si

 

Except the SR didn't have 4WS like the American SI did. I know 'cause I used to have an SI and now have an SR. All american SI's came equipped w/ 4WS, so there was never an actual 4WS trim, they were all just SIs.

 

I'm pretty sure that you could get the USDM Si without 4WS. I'm going to double check but I'm pretty sure it was an option on the Si, not standard.

 

my 92 Si is NOT 4ws

and, vin is BB2 (Si)

~boom

 

my SI has 4ws and 4ws trim on it.

 

ats....= atts = active torque transfer system...or something...i can never remember what the actual word are...but i think thats it