Is the Saker 2500W good for grout and tile?

Yes, that is its main use. The pressurized steam and brush attachments are meant to loosen grime in grout lines and on tile, though you will refill the small tank often on large floors.

Does it need to be plugged in?

Yes. It is a corded handheld unit, so it runs from a wall outlet and has no battery. Reach is limited by the length of the power cord.

How long does the steam last per fill?

Expect short bursts rather than long sessions. The internal tank is small, so you refill frequently, and steam pressure falls as the water runs low.

Can I use it on upholstery and car interiors?

Yes, with the fabric attachment. Keep the nozzle moving and test on a hidden area first, since high-temperature steam can affect some fabrics and dyes.

Is it a replacement for a full-size steam cleaner?

No. It suits spot cleaning and small jobs. For large floors or long continuous cleaning, a canister steamer with a bigger tank is the better fit.

What comes in the box?

The unit ships with a nozzle and brush-style attachments for hard surfaces and fabric. Check the included accessories before buying if you need a specific brush.