i was about 4-5 car lenghts behind a semi for 150 miles on the way back to cali a week ago, it was producing 28-29 mpg on my 91t, it's got an intake 2.5dp so it's basically stock, then again my motor's 1st cylinder is low on compression so i bet if the engine was working better then i might have gotten over 30mpg. but as people were saying it's not the safest thing to do, when they would change lanes, i would drop back a couple more car lengths to let them see i was there but i wouldn't ever try 20-30 feet, thats just crazy

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