E46, Z4 Differential Upgrade - 3.64 Original BMW

Product Details

The 3.64 differential is an Original BMW part and a complete, fully-built differential ready to be bolted in to your E46 3-series or Z4 Roadster/Coupe. The 3.64 ratio was standard on the Z4 2.5 automatic, which makes this an upgrade for both E46 automatic and SMG and Z4 3.0 automatic and SMG. It's also a big upgrade on all E46 and Z4 manual transmission cars as they came with 2.93 or 3.07 gear sets. The 3.64 is a huge 18-24% shorter than the stock 2.93 or 3.07. Having the shorter ratio will put you in a better part of the RPM band for any given speed. This makes the car instantly quicker. Since this is an Original BMW part it carries the same BMW two year warranty as any other new part. So there's no need to take a chance on a used part from a private seller. There's almost no downside! Note: depending on the model and your existing diff, you may need to change the output flanges to match the set you currently use. Swapping from your old diff to the new one is acceptable.

Examples: 2002 330i, 5-speed manual, 245/40-17" rear tires
Gear Ratio	Gear	Speed	RPM
2.93	4th	40 MPH	2,000 RPM
3.64	4th	40 MPH	2,450 RPM
2.93	5th	70 MPH	2,800 RPM
3.64	5th	70 MPH	3,450 RPM
3.64	5th	121 MPH*	6,000 RPM
* - Theoretical speed for 3.07 gears at 6,000 RPM. It doesn't mean this speed is actually attainable. It's only offered for reference.

This item fits the following BMWs:
1999-2006 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi
2003-2008 E85 BMW Z4 2.5i Z4 3.0i Z4 3.0si, Z4 2.5 = manual transmission only

Product Q&A

Lifetime Replacement