Gas economy 3800 vs 3800 Super Charged (Page 1/1) James Bond 007 DEC 18, 07:17 PM Which engine gets better fuel economy? The none supercharged 3800 or the supercharged 3800. Both engines are manufactured by GM. Stubby79 DEC 18, 10:10 PM Probably depends on the size/weight of the vehicle it's in. You'll find the S/C version is more efficient at producing more power than if you produced that same amount of power with a N/A version. In a larger, heavier vehicle, it would take more power to get it going and keep it going, so the S/C would presumably win out. But if you didn't need the extra power, you'd be wasting HP spinning the supercharger. Superchargers increase volumetric efficiency. That's my take on it. But I wouldn't swear by it! virtuetovice DEC 19, 06:17 PM Ive driven both a 3800 NA and a 3800 SC in the Regal/Century[same body mostly same weight] and have found that yes indeed the SC motor seems to have better fuel economy. It dpends on how you drive it though. In the city that SC has the ability to seriously drink some fuel James Bond 007 DEC 19, 06:44 PM Thanks for the info, Im in San Diego county and as the population keeps growing, Its going to be a waste of power...Thanks again. Old Lar JAN 18, 02:01 PM When I had my 99 Buick Regal GS with the 3800SC, I could get decent mpg (30 mpg) with a gentle right foot. However when I towed a trailer down to Florida when I moved, the car couldn't get much more than 16 mpg. Josh52894 MAR 12, 08:34 PM this isnt exactly a perfect response but i own a 1990 thunderbird 3.8 supercharged m90 just like the 3800 sc, it gets 22 on the highway at 70, i breifly owned a 92 cougar 3.8 NA, it got 25 on the highway at 70. they have diffrent transmissions tho so this may all be irrelevent. TK MAR 26, 05:01 PM In comparing my wife's 2000 GTP to a friends 2001 GT, the MPG was a wash. About 30 on the freeway if you keep it under 70.