Golf Gti optimal gear change rpm

[Jaydnisevil]

Just a quick question, that google and wikipedia failed to answer.
Whats the standard revlimit of a Mk4 Gti 1.8?
I believe the fuel cut is 6.7-6.8 but I just head that on a forum.

As for shifting point, normally you want change at around redline.. You want to shift at the point where you will retain the highest area under the torque curve. Its all about retaining a higher average..You want the most torque possible in the next gear coming.

When you shift from 3rd to 4th, the torque at the wheels is lower. (EG 600N atw in 3rd @6000, that the same rpm in 4th it may be 400) If you change at a point where the 4th torque will be 500nm you will have a better acceleration rate)
The manufacture usually would have geared the car to perform best with a change at redline (NOT FUEL CUT) Normally that will drop you back nicely onto a nice lump of torque.
There is no point changing at 6800 if the torque has already peaked or tapering in the following gear. You will be well and truly out of the range in 3rd and already over the hill in 4th.

[adzy]

For saving fuel a lot of people get confused with RPM vs engine load. The most economic way to drive is to drive as though there is an egg under your right foot.... as in using as little throttle as possible with the goal being to drive without using boost. The RPM may go up a little but it is better than mashing the pedal, using boost, and changing at low RPM.

As for SPORT driving I agree with keeping the engine in the meat of its torque curve. The MKV GTI is quicker when shifting before redline as the turbo's A/R ratios are a little too low to give good power/torque at redline. At 5000RPM the torque starts to dive and at 5000RPM the power curve flattens out then starts to drop off at 6200RPM. Between 3000 and 5500RPM is where the thick meaty power and torque are at!

When I was at Heathcote with the GTI I ran consistent 98MPH trap speeds when letting SPORT mode shift (6800 - 7100RPM).
When I manually shifted I was shifting at 6000RPM which gave trap speeds of 101 & 102 MPH...... pretty good proof of the theory once I found the best RPM to shift at it was time to go home - SPEWING!

[Jaydnisevil]

Absolutely right in regards to economy driving, basically you use more fuel with the more air going into your engine. Assuming N/A for simplicity: at 3000rpm wot, a 1.8L engine drinks 45L of air every second.. (Also assuming 100% filling efficiency) If your at 4000rpm and only using 25% throttle you will drink the same amount of air and therefore fuel (Not to mention cruise maps which will be leaner). By the time you factor boost in, well.. 3000rpm and 8psi it will be around 70l/s!! which equates to about 6200 at 25% throttle.

Another example is freeway driving, your fuel economy goes through the roof because your going light on the throttle. There will be position where rpm and throttle position is optimum, but thats for you to figure out It also depends how easily the engine makes torque and where..

We have a FG XR6T at home, and the trip computer shows that low throttle works up to a certain point. After that its more efficient to change down and use the low end torque with more throttle (which I found very interesting)