[ztech]

The G20 330i tune is a newer tune, and still hasn't been listed on the DME website (the F30 330i tune is listed). The company quoted me 52HP/55TQ gains, which is very close to the numbers that Dinan Stage 1 Bench tune. I can confirm that the tuned car, does feel quick enough off the line, to be consistent with those numbers, although I did not attempt any measured acceleration (0-60/Quarter) runs to help verify that. I should note that even stock, the car does get substantial wheelspin - enough so that getting a decent launch, involves a learning curve.

In S-shift mode/Sport Mode, even when your not stomping on the gas, the car is much more enjoyable to drive. There is a significant improvement in throttle response, and that responsiveness has been improved throughout the rev range, too. I love how linear and effortless the acceleration has become. Just tipping in, and very gradually advancing throttle, say through 40-80 MPH, and you feel a linear surge of power, that is much watered down with the stock tune. These improvements in acceleration have not come at the expense of violent, or even rough, gear shifts, either. The car is still smooth shifting (perhaps, in part, thanks to the 550nm/405lb-ft rated ZF 8HP transmission).

Inside the car, you can notice a more aggressive growl from the engine, though it hasn't become obtrusive for Comfort-mode driving. The tune updates the sport gauges from 300HP/300TQ to 400HP/400 TQ, and from 20PSI to 30PSI boost.

Maybe the best thing about the tune, was how the increased power, compliments the 330i's handling. I took the car through some twisty roads, and I immediately appreciated with how much easier it was to set myself up for the next apex. The tune highlights the car's ability to make lateral transitions, as the power level much better matches the chassis/suspension.

I wouldn't say the stock tune isn't good, but like a lot of other people, I've gotten used to driving the base models. With this tune, the 330i feels intermediate to the M340i - in other words, like it convincingly could have been "the 340i". Everything feels very stock, but much more racey.

On my long 3 hour drive back (averaging about 90 MPH) from my tuner, the first day of the tune, the car ran fine, with no issues. Unfortunately, I was running stock plugs with 39K miles on them. On the second day, after a long, 2 hour drive, followed by about 5 hard pulls from a standstill, upon restarting the car, the DME had clearly reverted back to a lower map - which felt comparable to stock. There were no misfire/knock codes that I could detect with the Bimmercode and MHD apps, and neither could my tuner shop detect anything via Insta. I did speak to DME Tuning today, and they did assured me they are not manipulating knock sensitivity, and that all factory safeguards are in place. They only confirmed that with the additional boost on Stage 1, the old plugs (39K miles), can quite likely cause a misfire, even running 93 octane. And DME Tuning did recommend 1-step colder plugs, which I wasn't running. Still, there is the possibility that some sophisticated, underlying factory or DME Tuning safeguard, (eg; temperature/low voltage at the spark plugs), is anticipating potential misfire/knock conditions, and tunes the engine down, before the trouble starts - and that might explain why there was no detectable misfire/knock codes.

My shop replaced the plugs with NGK plugs (stock heat rating), the car was fine on Stage 1, for a few hours of driving, but I had to have it tuned back to stock, for the dealer to service a recall. I will have to have some more time with the car on Stage 1, with close monitoring, to reflect on how it holds up.

I would recommend anyone who gets this tune to make sure they are on fresh plugs.