at the moment in the UK and due to rise to $130+ a tank by sept....

 

How did you break your car in? It sounds like it could be unseated rings, if your calc's are correct.

Did you change your breakin oil early? Did you run up to varying high rpm's in the latter part of breakin?

(Jeeze I feel like "Doctor I told you so".

But try your calcs again. Fill at the same station and pump (some air shut offs vary).

 

I never went above 3500rpm and above 65mph for the first 1500 miles, and I went really fast to break it in at 1500miles. I changed my oil already at 4656miles and it was already like this before I changed it, which means it already consumed so much before I changed the oil.

I will try to do a better calculation next week as soon as I'm back from a trip

 

I don't think your rings are seated. You changed breakin oil far too early. Now you have slippery oil, that retards breakin. Porche recommends first oil change @ 20,000 mi. You're not the only one who felt compelled to change early, but this may be a consequence.

 

DEETZ,

You can't rely on the car computer to give you an accurate reading of mileage., since it continues to average from the very beginning, including all idles. You must reset the computer or, even better, set your odometer to zero the next time you fill up, and use a hand calculator to figure your mileage the time after that.

I suspect you will be pleasantly surprised.

Jeff

 

Good advice......... and good observation...

 

I always reset the odometer to 0 whenever I refill, I had my car back with the new front bumper today and I just finished 20gallons with some highway driving, the thing beeps after 202miles so its around 10mpg, pretty happy with it.

20,000miles is not what Porsche suggests but its how long the oil can last, I'm pretty sure that there is nothing wrong with changing the oil too early

 

I always reset the odometer to 0 whenever I refill, I had my car back with the new front bumper today and I just finished 20gallons with some highway driving, the thing beeps after 202miles so its around 10mpg, pretty happy with it.

20,000miles is not what Porsche suggests but its how long the oil can last, I'm pretty sure that there is nothing wrong with changing the oil too early

 

You're quite simply wrong on both counts. Sorry.

 

correct me if I'm wrong thanks for the advice, but may I know where do you get the info from?

 

My CT reads ~12 average, I reset it often.

After a fillup it always shows a 355 mile range, never mind the fact that ~200 is the norm (I push the zero button as well out of habit).

Oh well, my family across in EU pays a whole lot more still...

 

I have done ring jobs. Let me explain:

A motor block cylinders are bored round. A piston is made round. A piston ring is made slightly larger than the piston bore, it is cut in the circumference, to allow for squeezing it into the piston bore. It thereby becomes out of round.

The ring is spread over the piston ring and settles into a slot made for it in the piston (there is more than one ring). The piston is inserted into the round bore and the piston ring is squeezed to fit in.

The piston ring is made of harder metal than the block, so when it rubs against the block it removes part of the block bore, leaving debri in the oil. The piston ring wins by making the block bore a little out of round; then your piston "is seated".

Porsche uses a special brakin syn oil (that encourages wear - to seat), and they recommend first change at 20K. Other manufacturers use dino oil which isn't as slippery & they used to change at 1000K.

If you take out breakin oil too early, you don't allow the two circumferences to match & you can get "blow by" = oil consumption & bad gas mileage due to reduced compression ratio.

I'm no expert, but that's my read - check me out.

 

20k miles is how long the oil can last, the point is that the dealer can save money by not changing the oil too soon on the cars because those oil can last for 20k miles. This is what I am trying to say. I have asked some expert and I don't think you are right, I am not trying to flame anyone, just to correct you

 

Torags: You might want to read this LINK

 

I appreciate your efforts to correct me.

For clarity: Did the expert who told you oil only lasts for 20K, do your oil change?

My understanding is that oil gradually degrades and is not like a light switch.

Did he feel that the Porche engineers are wrong when they recommend the first chage at 20K?

Your website is nice, but has little educational value. But thanks.. :-)