I was once considering a 335i until I test drove the 535. WOW!
I highly doubt a 135i will run circles around a 335i. The 335i weighs in at ~3500 pounds, the 135i comes it at a mere 100 pounds lighter at just under 3,400 pounds. My 535i weighs just under 3700 after I swapped out the awful Run Flat tires for lighter/sportier Michelin Pilot Super Sports.
Rotational mass affects the weight of a car much more than actual mass. The Super Sport tires weigh 4 pounds less in each corner, so that's a 16 lb weight loss from upgrading to these amazing tires. Anyways, 16 lbs of rotational mass is the equivalent of nearly 100 pounds of actual vehicle mass (meaning my 535i barely weighs more than a 335).
Needless to say, my 535i began running circles around 335i's. My point is, the 135/335/535 all have the same engine with the only differences being size and luxury. The weight differences are all minimal so the cars all handle very similarly. The cars are so similar that tires make a bigger difference than weight.
Get a 135i and keep the Run Flat tires...I will prove to you my point. Those run flats are such trashy tires that my 3700 pound 535i equipped with Michelins will out-handle your 1 series. After test driving the 535i I didn't even consider the 135/335.
08 535i - Platingrau Metallic, Sport/Premium
Mods: 15% tint - angel eyes - matte black kidney grills
07 335i - Sparkling Graphite, Sport
Mods: Coming soon
BMW Parts Online
Last edited by zach1328; 05-13-2014 at 11:30 AM.