What is Spec-G, Spec-A, ect...?

I see these used but am unsure of what these classifications are? What class would the tC, xA, & xB fall into?

 

Is there something specific you're thinking of? Are these classes for a certain event or something?

 

I've seen these titles mostly used in conjunction with cars. example: Honda Fit "Spec-D" Seen these in mags, tuner sites, product names,....Gran Tourismo.

I'm assuming it relates to the racing class of the car...?

 

Isn't spec-d usually a drift car? Usually, it is just a trim level for a car such as the old SS and Z-28 packages. It is just a "cool" way to identify different trims. And like ack said, it can also be used to classify different levels of cars in racing events.

 

So there isn't really a "standard" for these specifications for all events? I thought there was a car class system involved in it. I've tried a bunch of different autosport websites & can't really find a good explination. I was thinking if the Honda Fit in last months SuperStreet is a "Spec D" car that perhaps the xA & xB were as well since the cars are similar in design...but I realized the Fit that was featured had a completely different engine than the stock, consumer available engine.