The range estimates use different test procedures. BMW's quoted range uses the WLTP test procedure. China's CLTC test procedure is much more generous.

As noted in the article:

> "The Seal 08’s claimed 1,000+ km CLTC range translates to roughly 620+ miles — though real-world figures under EPA or WLTP testing would be lower. For reference, the recently updated Mercedes-Benz EQS 450+ claims 926 km under WLTP (575 miles) with its new 800V architecture and 118 kWh battery."

To compare the range properly you need to do a real world test of the vehicles on the same circuit in the same conditions.