I cannot give accurate fuel mileage yet ... still not driven regularly.
all I can say: with the 4.0 I6L I could only do 200 kms before my light went on in the dashboard.
Last time I did 160 kms with the LS1 in mixed city driving and the gauge was just below half ... looks like a 50% increase to my old setup
power steering pump return line was seeping because of too large diameter hose and the hack job of a hose clamp barb setup
(too many shortcuts taken by the shop .... grrrrrr) NOW FIXED!
another nice thing ... 20 kms mixed city and urban driving in the middle of a warm day with AC on and my coolant temps NEVER got above 200* F
But in the same occasion I was monitoring open/closed loop ... and my PCM never got out of open loop ... WTF!?
(no codes triggered!)
need to dig some more ... temp above 160*F should switch to closed loop ... except when the upstream O2s are defective? ... I need to check my tune as well! Eventually the PO of the caprice did not have a stock tune in the PCM after all? (too many DTC codes were disabled already and make me suspicious now
other than that ... here my other observations:
- with 4.88 and 33" tires and a tire size gear ratio adaptation via HPTuner I have a interesting shifting behavior :
1st gear stays engaged until 2000rpm ... which might be nice sometimes ... but on the other hand the shift into 2nd comes surprisingly when turning into a corner and is still abrupt somehow... quite confusing
- shifting behavior and torque management work much better if I have the courage to step a bit more on the throttle
- there is a surge with part throttle for a second or two after shifting into next gear SOMETIMES ... but goes away impressively mighty when pushing the pedal slightly.
- acceleration is amazing ... with no effort and no time sluggy is at max city speed of 80km/h
- from 80 km/h I am in 4th (OD) with 1500 rpms ... if I accelerate I simply see the speedo needle climb ... moments later I am running 120km/h at 2600rpms
... like sitting on a bungee rope driven sleigh
(superior to any I6 4.0 I could drive before ... just mighty truck like)
I am REALLY glad I did the Vanco Big Brake conversion just before the swap !!!
All in all : wow ... still have no guts to press the skinny pedal hard ... now really curious about off road behavior ... eventually need to tamper a bit with torque management and shift points