Following the failure of the M114, a new reconnaissance vehicle was needed. One of the answers was the XM800 Armored Reconnaissance Scout Vehicle (ARSV), for which two contracts were awarded: One to FMC for a tracked vehicle, the XM800T, and one to Lockheed for a wheeled vehicle, the XM800W. Unfortunately, both of these vehicles ended up being cancelled and superseded by the Bradley. This suggestion will focus on the XM800T.
The XM800T was a tracked light vehicle intended for scouting. It weighed 8618 kg (around 9.5 tons) loaded, and used a Detroit Diesel Allison 6VT-53T engine, which was a version of the Sheridan’s engine tuned down to 270-280 hp for better reliability. This gave it an excellent power-to-weight ratio of around 29 hp/ton. The top speed was 88.5 km/h and the reverse speed was 40.23 km/h. On top of this, the vehicle was fully amphibious with a swimming speed of 7.2 km/h.
The vehicle’s light weight was achieved by using light armor made of aluminum alloys. The vehicle was operated by 3 crew members. It was fully stabilized and fully turreted, coming equipped with a laser rangefinder. I do not know if it had thermals, but from what I understand, it had some form of ground radar (though I do not know the specifications for it). The main gun is a 20mm M139 autocannon. This is a US-built version of the Hispano-Suiza HS.820/Oerlikon KAD, the same gun as found on the R3 T20 FA-HS. It had access to APDS, the same as is available for the Wiesel 1A4, Marder 1A3, SUB-I-II, and Type 87 RCV (P). It also had a roof mounted M60 7.62mm machine gun.
In War Thunder, I see the XM800T as being a counterpart to the Wiesel 1A4. Though bigger, it boasts a full turret with a stabilizer and a higher top speed. On top of this, it’s amphibious and may potentially have a type of ground radar. It would have the same ammunition, but uses the slightly faster firing Oerlikon KAD.
Thank you for reading my suggestion.
My old suggestion for the vehicle has a list of additional sources as well that had more information, but unfortunately several of the links don’t work anymore: