EViews.com

Hi.... Sorry about my English.
I'm a final year student. my research is forecasting petrol demand. i want to fit GARCH model. i am using 260 weekly data. IS there a method in EVIEWS to find optimal lag to fit GARCH model. My data set has only one variable. plzz reply me...

No, EViews will not automatically determine the best lag.

So how should i select lags. What is the maximum value that lag can take.

You will have to use economic theory to judge.