That's because it's a turbodiesel. They have virtually no torque under 1,500rpm. Talk to www.superchips.com . But it might be unwise to muck about with BMW Efficient Dynamics mapping. You can't have everything. More torque at low revs will involve more fuel being used so economy may suffer and turbo life may be compromised. With other engines, Superchips has got them to tug well from around 1,200rpm, but that's about as low as it goes. The best low speed diesel slugger is the big D5 in the little Volvo V50 manual. That pulls from about 800rpm.