Here's the 2001 Volvo VIN decode if its of any help to you, it doesn't state the engine HP rating, but will get you to engine type. So according to the VIN you poste, the vehicle is:

YV1 = Volvo
S = V70
W = Wagon
58 = 2.4L light pressure turbo

CARS
1-3 WORLD MANUFACTURER IDENTIFIER
YV1 = AB VOLVO, SWEDEN

4 SERIES
N = C70
R = S60
S = V70
T = S80
V = S40 OR V40

5 BODY TYPE/RESTRAINT SYSTEM
C = CONVERTIBLE 2 DOOR WITH DUAL AIR BAGS (FRONTAL/SIDE)
K = COUPE 2 DOOR WITH DUAL AIR BAGS (FRONTAL/SIDE)
S = SEDAN 4 DOOR WITH DUAL AIR BAGS (FRONTAL/SIDE)
W = WAGON 4 DOOR WITH DUAL AIR BAGS (FRONTAL/SIDE)
Z = V70 XC AWD WAGON 4 DOOR WITH DUAL AIR BAGS (FRONTAL/SIDE)

6-7 ENGINE
29 = 4 CYL: 1.9L DOHC TURBO
53 = 5 CYL: 2.3L DOHC HIGH PRESSURE TURBO
56 = 5 CYL: 2.4L DOHC LIGHT PRESSURE TURBO (C70)
58 = 5 CYL: 2.4L DOHC LIGHT PRESSURE TURBO (S60 OR V70)
61 = 5 CYL: 2.4L DOHC
90 = 6 CYL: 2.8L DOHC TURBO
94 = 6 CYL: 2.9L DOHC

8 EMISSIONS
5 = S40 OR V40
D = C70, S60 TURBO, V70 TURBO OR S80
N = S60 NON-TURBO OR V70 NON-TURBO
R = S60 NON-TURBO OR V70 NON-TURBO

9 CHECK DIGIT
& = CODES 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, OR X ARE VALID

The information should be in your owner's manual in the back. It is not a 2.3T as that is the V70 T5. Your's, as your title says, is a 2.4 liter T (T for Turbo). so, the lesser of the horse power numbers...what was that, 220? Of course, you could get your ECU tuned by someone like IPD (www.ipdusa.com) or someone else and increase your HP by another 25-30 or so. If you do the downpipes, you could get a bit more on top of that and it will drive like the higher horse power car....but it's not really necessary. My wife' has a 2.5T...very similar to yours. It spools up quickly on the low end...much more than on the high end. I like that we can get on the intertate via the on-ramps very quickly. There is enough speed on the top end too...we aren't on the autobaun so it's not an issue here in the U.S. to have more power. The only modification I've done to her car (besides IPD antisway bars and heavy duty endlinks) is a K&N air filter which seems to give it just a bit more umph.
By the way, you'll get used to your car going like a rocket and adjust your right foot accordingly. The T5 will feel even more like a rocket than your car, and the "R" has 300HP, so it's a REAL rocket. Enjoy your new car and welcome to these boards!
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.