HD Top Speed

MemphisDoug · March 15, 2002

Just for kicks, I wanted to see what the top speed of my 2500 HD was last night on the expressway. I have the 8.1 and Allison transmission. Anyway, the fastest I could get the thing going was an indicated 97 mph on the speedometer. I figure it is probably computer governed but I thought the usual speed that they governed non speed rated tires was 107 mph. Any other experiences out there?

1BADHD · March 15, 2002

Before the HPPIII it was 97 also. I have it set at 126 now and have not hit that yet but I hit 100 and it kept climbing till I shut it down.

CMNTMXR81 · March 15, 2002

That would be because all GM trucks have had a speed limiter. It goes off at 99mph, yours showed 97 which is not uncommon for it to be off slightly.

Unless it's removed, none of us can go faster than 99mph.

Larry · March 15, 2002

My HD shuts down somewhere around 99 MPH.

I’ll say one thing though….the fuel shut off is much more smooth than my 98’ Z71. The Z71 would jerk violently when I would hit the speed limiter. The HD just stops climbing in MPH and steadily holds the top speed.

Could be worse, if you own a P or W RV chassis or step-van with an 8.1, the speed limiter is set at only 75 MPH.

RedHawk · March 16, 2002

99 when stock but 128 now..I have run the truck about as fast it can go and it runs out of steam at about 4500 rpm in third.. Not sure how fast that is but I think around 115 mph..Just to big to push 6100 lbs through a 100 plus mph wind..

I guess if I hit the nitrous I could hit 128..hehe