I feel like a dumbass asking this but does anyone know what kind of oil I should us for my 90. I just got it and want to change the oil, My father in law says "what in the hell did you buy an audi for, don't you know you have to spend a ton just to change the oil" Duh!! Because it's an audi. So before I go and reck something that is functioning perfectly fine, I want to make sure I'm using the right stuff. Owners manual says "API sf/sg" , Is thing a synthetic oil? Do I need to buy this from a Audi dealership or can the right kind of oil be purchased at a checker auto parts or walmart. Figured either way experience is the best way to go.

Thanks, Scott

hmm, can you wait, I will post my article about oil.

API SF/SG is not a type its a grade.

you need a syntetic oil, for best overall protection.
What engine you have and what climate you have?

Thanks

I have the 2.3 5 cylinder, and live in Minnesota. I was reading some of the other posts about oil.... Am I able to tell if synthetic oil is being used right now? Also, I take that I should not go right from conventional oil to synthetic. Do you suggest a certain crossover period, and what proportions would you mix, if it was you.

Thanks again, Scott

personaly, ye I do to have crosover period:
there is almost no way to tell if its syntetic or conv. exept some tests.

any way,
there is cople of ways.
first simply jump straight to syntetic, but will have to change it really soon.
second change to syntetic blend and then to syntetic.

syntetic blend is from castrol
syntetic I recoment from mobil1 (note mobil is conventional, mobil1 is syntetic)

use 10W-40, its like universal.
teach a stupid monkey, where is michigan?
do you have a oil presure gauge (auxilirary gauges)?

I am really tired of hearing all this BS about transition between conventional and synthetic motor oil. If you are going to race then you will need to flush out all the old oil. On an old tired engine you are not going to notice anything or do any harm.

I use 10W-30 synthetic or conventional and change it on a regular basis, 3K for conventional, 4.5K with synthetic. I have switched back and forth between conventional and regular oil. The engine didn't blow up and oil seals don't leak even with 186K on the clock.

true, true.

but still, have you seen what happens if you blend syntetic and conventional, and work it through. wow it ugly.
any way, in long run the syntetic would be cheaper that conventional.
syntetic can go up to 10000 miles easy with syntetic mobil1 extended.

in the periods of 3 to 4.5 K miles is not really large, you can easy jump from one to another.
the oild can go easy from 10000KM to 15000KM, thats what manual in europe says.

ya, It's mid-western united states, The weather goes from anywhere from -30 to 40 degrees F, and the summers are 70 to 90 and humid.

I do have the aux. gauges in my car. Oil pressure is good- 2.5 to 4 bars.

My manual also says 10,000 miles between oil changes. And the only time I race is when I'm late to work

good
use syntetic
and 10W-40 be good
or 15W-50

go by manual

Thanks for all the help, I greatly appreciate it.