the guage on the car when driving normal around 3/4k the guage is above the middle but today i gave it a bit of a abuse to the top end of 4th the needel went below the half way point is this normal? as on my old subaru the higer the rev the higher the presure?

regards
ian

Maybe a pressure bypass kicks in at some point to protect seals and stuff, so drops the pressure slightly while it is open?

Yeah the pressure should rise with the rpm as the oil pump is running straight off the crank.
Check your oil level first of all. If it is low then you could be getting oil surge and starving the system of oil which is not good at all.
Other than that is could be an electrical fault. Possibly a bad earthing point etc.

going to give it a oil and filter i think it was serviced when i brought it but not sure what oil they put in it.

what oil should i use and how much of it does it take?

Cheers
Ian

check your oil using the "dip" stick.
if it is a fairly clear/light color your oil should be good.
oil is changed every 3000-15,000 miles/kilometers,
depending on who you ask.

in reality, you are not so much changing the oil as you are changing the oil filter, which you can not do without changing the oil.
a clogged oil filter is bad, mmm kay, very bad boys and girls...
it is a good idea to change the oil filter as often as you feel necessary depending on your driving.
but it is only required about every 3,000-7500 kilometers or about every 5,000-10,000 miles.

premium filters and oils still need to be changed at regular intervals.

constant EXTREME temperature change however is bad for oil, and therefore, if you are running your car, let us say, at high RPMs during the winter,
it may be a good idea to change your oil/filter before and after winter time?

here in Japan, it is law that you must have all season/winter tires on your car from late fall until mid spring.
most people have their tires rotated at least once in between these dates.
if you are doing it yourself, it is just common practice to change your oil/filter when rotating your tires or changing from winter wheels to summer wheels.

use 4 quarts of (synthetic?) 10w-30 motor oil, that should be fine for where you are at.

these are common synthetics that i know of:
mobil 1 synthetic, castrol syntec, royal purple

of course there is the synthetic vs. crude debate; synthetic is probably better for the environment?
i know plenty of people who can argue both sides, and i will not do that here.
there is probably a thread about it somewhere on this forum.

[quote name='ian_ujc' post='692308' date='Sep 28 2009, 11:24 PM']what oil should i use and how much of it does it take?[/quote]
The 3SGE takes 5.1L Most of us use Castrol Edge 5w30 fully synthetic. You can also run 10w30, 10w40 & 5w40 with out any problems. I wouldn't run anything thicker or mineral as it can cause issues with the VVTi solenoids.


As for your pressure dropping at high rpm (6K+) it's would seem it's pretty normal for Altezza's. Mine does the same. I'd never taken any notice until someone asked on tezzaworld. We all had the same result.