Acoustic windshields use a sheet of acoustic vinyl sandwiched between two layers of glass to reduce noise levels by at least 6 dB at certain frequencies and 2-3 dB overall compared to ordinary 5mm glass. They can reduce noise by up to 90%, which is 60% more than standard glass. Acoustic windshields also contribute to better fuel economy and offset the need for thicker, heavier glass. When replacing a windshield, look for the manufacturer's trade name or letter "A" to ensure an acoustic glass windshield.