I have seen several mentions in this forum that the car's performance changes dramatically at 5000 miles. Is that fact or fiction?

Does the ecu change timing or something else at the magic number 5000?

Just curious since I now have 5002 miles on my roadster. Should I expect to see anything different. Or is it hype?'


Not looking for the doors to change into lambo or wings to sprout or even to have an extra 50 HP. But, curious if the 5000 mile barrier has any credibility.

 

I think what most people are saying is by 5000miles the motor is broken in, transmission has loosen up etc. When the motor is broken in properly the rings are sealing better and generally you get just a few more ponies. The tranny is shifting smoother and the gears meshing better just makes it quicker to shift and get down the road.

Also, by 5000 miles you realize this car has sweet spots and you know how to drive it, shift it and when to do so.

My car has 11,000 miles on it. After 5,000 miles I went to full syn oil. It seems that after another 5000miles it is running even better than at 5000 miles. I think it takes quite a bit of time to break these motors in since they are designed to last 200K miles or more. Believe it or not, my 300ZXT ran better than it did off the showroom floor with over 200K on it. It was really loose and just wanted to rev. I'm glad it stayed together and took the abuse for so long. I can't believe how long these motor last if you take reasonably good car of them.

IMO

 

yea 5,000 miles was around when my radio stopped working, the axles started clicking, 2nd gear started grinding, and about 120 rattles in my interior came out of nowhere.

 

car did seem to gradually get faster (1/4 mile times) but I believe I was also getting better at driving it. Up until about 20k miles, that is when mine really seemed to gain some power. Like at 20k the ECU went into full throttle mode considering the car to be sufficiently broken in. I dropped .6 off the 1/4 mile at that time. And I know it wasn't all the JWT popcharger I added around then o.O

 

Definitely. At 5,000 miles, the ECU is designed to kick in an extra 20 horsepower. If you are driving and the odometer crosses 5,000 miles, be careful: the car will take off like a rocket.

 

yeah the Z is a carefully designed machine. at 5000 mi you'll notice a HUGE difference. what's the difference you ask? your odometer will click over to 5001.