Back in the day, the lag on turbo cars went something like "stomp on gas, one Mississippi, two Mississippi, three Mississippi" and then the power arrived. These days anything past one Mississippi is considered very laggy, and most have it down to half of that, or the same lag you get driving most cars with specific California emissions.
If you have the older Tahoe with the LT1 5.7 liter then you will find the step-off of most modern cars pretty soft due to emissions regs. That LT1 was a beast low down, and if you have the 4.1 gear in that truck then you will think almost anything modern has lag.
GM 4-cylinder engines could be pretty nasty for NVH, especially their 2.4 engine in the smaller cars. Japanese and German 4-bangers are generally better in that respect. As for what BMW did for an extra 1mpg, is it really as little as that? I thought the new 328/528 did much better on the highway that the old sixes. Besides, these are EPA numbers that I take with a bucket of salt.
Most motoring magazines can never get near the EPA numbers with turbo cars because they are more sensitive to how they are driven. Drive them like a normal person and the EPA numbers are well within reach with a turbo car, especially on the highway.
My biggest beef with the latest 3 and 5 Series BMWs is they have grown so large. The 3-Series is now at least as big or bigger than a 5-Series from the late 1980s or 90s.
My Tahoe is a '97 with the LT1, 3.73 rear end. I drive around town with the overdrive locked out (in 3). Performance is quite good. I think I'll hang on to it awhile longer...
I didn't time the 328 with a stop watch, but I got to at least 2 mississippi. I hit the gas, there was the delay before downshifting, so the motor was bogged down and couldn't rev, then after downshifting the delay for the motor to rev up, then the turbo finally kicked in.
I looked up the mileage numbers for 2011 and 2012 328/528. 2012 was the first year of the turbo 2.0 4.
Mileage is city/highway/combined
2012 528: 23/34/27
2011 528: 22/32/25
2012 328: 23/33/26
2011 328: 18/28/22
The 328 numbers are really odd - they are worse than the 528, which is bigger and heavier. I think the 2011 328 may have a different transmission than the 2012, while the 528 uses the same for both years.
At the time, I was most interested in the 5 series, so that is where I remember the 1 mpg number from. City mpg only improves from 22 to 23, highway and combined only improve 2 mpg. A rather poor compromise.
Just for grins, I looked up the 2012 535 and 328(turbo 3.0 I6). Both were listed as 23/33/26.
That really makes the turbo 4 look like a poor choice.
What really gripes me is that all of this - downsized engines, electric steering, stop-start systems, etc. are driven by regulations, not because people actually want this stuff. Then the dealers try to BS me and tell me they are 'enhancements'.
The one time I actually got a halfway truthful response was from a dealer when I was looking at a Mustang GT last year. I asked if it had electric steering, he kind of hung his head and said, 'Yeah, I know....but it isn't that bad."
