- Feb 1, 2007
- Dallas, Texas
- 00 4Runner | 02 919 | 87 XJ6 | 86 CB700SC
Most likely, considering that the Series III was quieter on the outside with the Federal spec mufflers than the Euro/ROW ones, to use one example I am personally familiar with. They also sometimes came with insulation that was optional or simply wasn't available for Europe.There's more to insulate, probably - around here limits for a car are 74dBA "driving noise", that's at 3/4 revs in 2nd or 3rd under 50km/h at full throttle.
Quick googling about the US was inconclusive, some sources state 95dB - that would be one hundred times as loud. If true then no wonder you need more noise insulation. Probably some different measurement though.