Hey guys, I'm quite a novice with cars, don't know much about tuning them up or modifying them, so go easy on me please guys

Basically i know what i want done to my car but before i start changing anything, i just wanted to know if it would have any negative effects on my car. I.e. higher fuel consumption, slower performance etc.

I'm wanting a new exhaust or back box on my car just to give it a more meaty sound, but nothing to extreme. What effect would it have on my car if i got a bigger exhaust/back box? (Other then sound, obviously. )

And I'm also looking for bigger alloys. (14" or 15") its quite a small car, so it's pretty difficult to find nice looking alloys that could fit. What tyre dimensions should i be looking for? or do any of you guys know of some nice alloys that fit a Fiat Seicento Sporting?

I'd really appreciate any help or advice given, and sorry for my newbie questions

Lewis

Forget 15'' you wont go anywhere quick, in fact you wont go anywhere and you will have to modify the arches

14'' you will be ok search gallery or internet for ideas and inspiration, everyone has different tastes no point wasting our breath if its the opposite you like

Backbox will be ok you wont see any loss in MPG as its just the backbox, if it was a full system you might see an ever slightl decrease in MPG

With any modifications expect to see some differences as they obviously arent standard items

Dont forget to check your insurance before doing any modifying

With 14" wheels you might have to fit the Punto differential to get the correct gearbox drive ratio. Gears that are too high make the car slower, use more fuel and stress the gearbox internally.

Make sure you get wheels with the correct offset so they dont rub the suspension etc affect your steering geometry which is potentially dangerous.

195/45/14s will fit fine on 6J rims. No vhange to gearing.