If the car you are driving sounds like a tractor
then you have the MJet which is Diesel.
If it's very quiet then you have the TJet, which is petrol.
I don't understand how you can't know, especially when you have purchased the car
TJet has 120bhp standard, but some owners have noticed theirs producing more when put on the Rolling Road (RR). About 130 - 140 i think some owners cars have produced.
Mjet has 130bhp standard, but again, some owners cars have produced more on the RR.
So, depending on which one you have will depend on how much power your car will produce when remapped.
I think the TJet has been producing about 150bhp give or take a little, while the Mjet has been mapped to over 200bhp from just a remap alone.