[2012one35i]

Hello all, I have been unable to find anything specific about the 135i intercooler, whether it is undersized and needs upgrading, or adequate for below 400 crank horsepower. Well, I called two different BMW parts departments and got the same answer. All 135i's, 335is's, and 1 series M cars use the same part # intercooler. It seems there is little reason to upgrade the factory intercooler for most street driving circumstances, however, those who track there cars often may disagree. I have contacted Dinan, Burger, and BMW Service Department, and the only people who recommend upgrading the intercooler are the intercooler manufacturers.