Well without changing gameconfig, you won't be able to use add-on peds.
I might be dead, so don't waste your time here.
Posts made by V4D3R
RE: Is there a way to play GTA V with the same video settings and FPS,but after installing a mega replace cars pack?
Most likely the vehicle replacements aren't very well optimized, and doesn't have LODs etc. So you shouldn't be surprised if your FPS drops. 200 custom vehicles spawning in traffic isn't a great idea, and FPS will drop even lower if you use any graphics mods.
The answer to your question is kinda obvious, you can't really do anything about it except for lowering graphics or removing replacement vehicles. Performance and quality can't be increased at the same time. All the FPS boosters or RAM cleaning software will NOT help, don't use those.
If possible, get a desktop, no matter what manufacturers say, laptops aren't really good for gaming.