40 pieces of sod- - - - - eek eek eek How much does that stuff weigh? It's just possible you were at, or over the payload limit, and there's nothing wrong with the performance. It won't hurt to check the timing, fuel filter, etc., though. That kinda reminds me of the trip back from the concrete plant with a bed full of sand and gravel to feed my mixer. That old Ford F-150 wouldn't get over 45 MPH, but the payload was about 2 tons!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!