If one uses the Yohoo stock price chart for RDS-A (maximum time - since 2005) and then adds CVX, xom, tot and bp as comparisons, I find the following (order of magnitude) gain during the last nearly 8 years:
cvx +100%; xom +50%; rds-a +0%, tot -20%; bp - 40%. rds is therefore middle of the pack but not near cvx nor xom.
I used to hold BP as a DRIP but sold it last year for tax purposes, taking a loss. Is it fair to go back 8 years? How about 3 years? I used Marketwatch to compare several oil companies and Exxon and Chevron have the lowest dividend rate. Should that also be considered in deciding what to purchase? Both Shell and BP are ARDs; does that make a difference?
Yes, dividends do make a difference when calculating total return (stock price appreciation + dividend).
The problem with selecting a specific time frame for calculating return is that it very much depends upon the starting point (as you point out). Using something less than 5-10 years is misleading (my view) in that it all depends upon the staring point. For example, RDS just reported a very nice total return of 40% over the past three years (13+%/year, simple return). That was cherry picking and disingenuous...over the past year, total return was negative; over the past two years it was about equal to the dividend (4-5%/year). It is better to take the same starting point every year (to get a better comparison) - or to take a very long view to get the average over several years (for RDS, the split price in 1987 was about 55; it is now about 65...so, the total return is less than $1/year from stock appreciation + the dividend --- so, the average over that period is very close to the dividend (or around 5%/year simple return - a lot less if compounded).