Is the word pneu the same in Brazilian and European Portuguese?

Yes

The spelling, meaning, and grammar of the word "pneu" are identical in both Brazilian and Continental Portuguese. The only difference is the pronunciation of the diphthong "eu." In Brazilian Portuguese, the "e" is typically pronounced more openly and clearly. In Continental Portuguese, the "e" is often much more closed or even reduced, which can make the word sound closer to "pnu" to an untrained ear.

Brazilian Portuguese Examples

1. O pneu furou no meio da estrada. (The tire went flat in the middle of the road.)
2. Preciso trocar o pneu do carro. (I need to change the car tire.)
3. A calibragem do pneu está muito baixa. (The tire pressure is very low.)
4. Esse pneu está muito gasto e perigoso. (This tire is very worn and dangerous.)
5. Ele verificou todos os pneus antes de viajar. (He checked all the tires before traveling.)

Portuguese Examples

1. Tive de mudar o pneu porque estava furado. (I had to change the tire because it was flat.)
2. A pressão dos pneus tem de estar correta. (The tire pressure has to be correct.)
3. Este pneu parece estar com um prego. (This tire looks like it has a nail in it.)
4. Onde é que posso reparar este pneu? (Where can I repair this tire?)
5. O pneu está com pouca pressão. (The tire has low pressure.)