1GFE Engine is a little underpower as compared with JZ Series but domestic crowns are equipped with 1G-FE Engines
and there is a lot of power not compared with JZ series. JZ is a true performance engine designed only for performance purposes and not for economy. i am using 1G-GE Variable induction engine in my Crown.
and yes economy along with power is very smooth as compared to JZ Series.
Crown has 3 variant of engines M Series is a bit sluggish and fuel gulpy i had driven all of crown engines and do Had A UZS137 with me also with genuine 1UZ-FE V8 its only for performance purpose and i dont expect economy from it gives me 5/L in city and 7/L on high way on average cruise speeds of 120KM
also had an MS135 90 crown with 7M-GE engine and yes power is amazing but the engine is rough and not reliable on maintenance. So swapped it with 1JZ-GE VVTi along with 6 speed Transmission. the engine is smooth and good in economy but if i compare the power curve with 1G-GE they both are same in performance.
i also had an crown MS122 with 1G-FE with genuine w58 Manual transmission and no doubt it is a smooth engine along with handsome fuel economy i easily manages to get 9-12 km/L in city drive depends on rush conditions. and on higways and motorways i get 11Km/L with the average speed of 100-140 km/h speed limits and i do enjoy its power curves on high revs. I think you had driven the 1G-Swapped crown on old Chasis or body swapped crown.
I Do had a crown with genuine 1G-Fe Equipped 1994 Sedan with chasis code of GS-141 and it was smooth and fuel efficient. And also had kept a crown with body swapped of 1992 with 2L-TE and when i swapped the vehicle with 1G-FE it was a waste of money and later founded that Differential Assy Were not matching and when swapped with 1G differential all things were balanced again.
So i will disagree with you on this matter everyone has different experience with different engines.