Judging from the tank size, one wouldn't expect the SU-101 to be that well-armoured. It is basically the exact opposite of an ambushing vehicle. This and the following tank's role are assault guns, meaning that they're fighting on the front lines, using their armour and powerful guns to shift the battle.
This Soviet tank destroyer is quite full of surprises. Not only does it boasts tough frontal hull and superstructure armour, but it also moves fast over the battlefield. This allows you to take crucial positions early on and intercept enemy tanks. Even though the armour is thick, you're far from invincible – avoid exposing your vehicle for too long. Take a shot and retreat into safety. You may try to angle your tank slightly but be careful: Too much and you will expose your weak sides.
While the SU-101 may be fast going forward or backwards, but the traverse speed is atrocious. Keep mobile enemy tanks at a distance. If you let them too close to your tank, they will easily outmanoeuvre you and pick you apart. It's best if you focus on cumbersome heavy tanks and have allies as a backup.
The top gun is the 122 mm M62-C2. With great penetration value and good damage per shot, this one works best in close quarters. Peek out, take a shot, and reload. Your reload time is rather high, make sure you can reload behind cover or else the enemy will pay you back double. The accuracy is too low to shoot at most weak spots but as mentioned before, the penetration is good enough for you to not worry about it too much.
To make your gun work the best possible, we recommend mainly reducing the reload and aiming time. Those pieces of equipment will help you both shoot more frequently and land the shots more reliably. In case you fear about your tracks being blown off frequently, leaving you like a sitting duck for too long, mount a Toolbox instead of the Improved Ventilation.
Of course, Repair should be the number one skill you go for as turretless vehicles are especially vulnerable if their tracks are destroyed. If you wonder why we suggest "Snap Shot" for the Gunner, well, this bonus works both during turret and gun traverse.