How to get better freeway performance?

[Griffin]

I've had my 99 Conquest Seca 1.8 manual for some time now, and absolutely love the car. The only issue I have at the moment is it sits at 3k+ revs whenever I'm on the freeway. In the future, I'm going to be doing a lot of distance driving and this might be a bigger problem. Trying to work out if I should get bigger tyres, an aftermarket dif, or swap out 5th gear/final drive. What's the easiest solution, and has anyone dealt with this before?

[chrislb]

I had a 97 Corolla Conquest sedan that I used on the highway alot to travel to work. Mine was a 5 speed it had 17inch rims and 60 profile tyres, it got good gas mileage,speed read a bit high from memory, sat under 3k at 100kph, good set up, I also got stiffer shocks all round and it handled ok too with 195's Bridgestones