Use of a fuel composition for improved performance of diesel engines with direct fuel injection

Use of a fuel composition for improving the performance of a diesel engine with direct fuel injection, wherein the fuel composition comprises an amount of relative higher than or equal to 50 wt .-% of a fuel relative to the total weight of the fuel composition and from 5 to 100 ppm by weight to the total weight of the fuel of a quaternary with a thermogravimetric includes ammonium salt (TGA) -weight loss of more than 50 wt .-% at 350 ° C, wherein the quaternary ammonium salt comprises a compound of the following formula each of which is selected from R