Volvo Cummins ISX450 or ISX500 which one is better?

It's the same engine just one is rated at 450hp and the other 500hp.. you could just get the 450 uprated to 500.. no? Assuming they have the same torque rated driveline..

 

If the engine is the cm2250 the 450 can be uprated to a 500 by just having the ECM flashed. Cummins South Atlantic in Charlotte quoted 250 to flash the ECM as long as there is no password on it. 350 if there is a password.

 

The difference is the tuning. You will actually get better mileage with anything above 485 horse because it makes the torque jump up. Shifting sooner. Should just be a plug n play at a Cummins shop. I had a prostar at 485. Radical amount of grunt for a company truck. Now I'm in a dd15. I want my red head back