Dear Nabeel,

The car you are owning is auto transmission whereas your friend is owning manual gear transmission so there is difference as auto transmission vehicles have lesser power compared to manual thats why it shows same rpm when you run in 5th gear and your friend runs in 4th gear.

Hope this satisfies your query.

I think Vikesh misunderstood the question. Your's is 5 speed automatic and your friend's is 4 speed automatic, the main difference is the gear ratio. But as it is showing the same RPM for both, that means that the ratio is almost same for your car's 5th gear and your friends' cars's 4th gear. To make it easy for you, the sproket size of both car's top gears is same. The advantage of 5th gear is better fuel efficiency because of better gear ratio for different speeds.

The RPM which yours' and your friend's car shows at 120kmph must be 3,000 not 30,000.

get ur car checked..... in my view if the RPM is absolutely the same...den how wil u attain better fuel economy ??....... pls note it again properly...... ur car should be at slightly low RPM wen at the same speed and at the same road..(all other conditions same) bt the RPM wud be just slighty low...dats it.