Home Forums Gear Hunting Trucks and Four-Wheel Drives 06 Silverado Top Speed ?

Z71 , 5.3L

Do these vehicles have something in the computer that limits the top speed ?

Mike

Yes.

The top speed is regulated to the speed rating of the tires it left the factory with. This can be changed with an aftermarket programmer

kup

Well that sucks , I'd be curious as to what that truck would do unimpeded , as it is right now 100 mph


Mike

Why don't you check the speed rating on your tires' sidewall and let us know what it is.
I'm curious about this now because I think there are some speed ratings on tires that are way under 100mph, and I've never heard of a car or truck that would only top out at, say, 75mph. Maybe the lower speed rated tires don't come stock on any cars or trucks and that's why...?
Interesting concept.

So far as I know the truck came with Firestone ATs which have a speed rating code of S or 112 mph

With Firestones history I'd think that maybe 35 mph would be safer


Mike

The Michelin LTX tires on it now have the same speed rating , they are dealer installed tires that were put on because the Firestones were recalled


Mike

Fixed it for ya.

Hey now !! this is a pre-obama truck , it's one of the good 'uns


Mike

I've gotten a tick over 100 with mine. No idea what the speed rating on my tires is though, 10-ply coopers. 4-door 06 Z71

Not sure about the Chebby, but if you remove the ABS fuse, or disconnect the vehicle speed sensor, the speed limiter does not work. Was able to squeak 123 mph out of my Cummins (GPS measured) before I ran out of gear. (Strictly in the interests of research, of course). Governed top speed on my truck is 108.

Research , yes , that is what this is about


Mike

Well how the heck you supposed to know how fast your truck goes if you don't "research" it?

Holy smokes! I bet it felt like 150 in the truck. What rear gear do you have? Mine is a 3.54 (front and rear obviously) and I love how the truck feels accelerating from about 60 to 80.

3.73 gear, went to 3400 rpm, 200 over redline. It actually felt pretty good

With my older '91 Chev pickup with 4.10 gears and a 350 engine, anything over 75 sound's like engine parts are going to start flying.

My 98 GMC with 3.73 axles, 454 cu.in. engine and 5 speed tranny shuts down at 102 mph. Always intended to get rid of the dang chip that causes that. I think it would go a lot faster because it's not much of a strain to hit 100 mph.
I'm not sure about this, but I think it's computer chip thinks it has 4.10 axles because I get the best hiway fuel mileage at 75 mph or about 2300 rpm.

Had my '06 Sierra Z71 up to "a hunnert" a coupla times. Aluminum 5.3L, 3:43 gears. Got up there pretty quick, never tried to see how much faster it would go and now it's gone.

Ain't had the 2010 Chebbie Z71 over 90, so far. This one has 3:08s, might take a tad longer?

My 08 Dmax tops out at 98 mph...."fought" with my dealer to up the top speed and they would not...top speed is dictated, as others said, by the tire rating it left the factory with....

My Banks tuner will not change the factory code....other tuners will....I gave up on increasing the top end and just use the 480 rear wheel ponies to get to 98 quicker when I feel the urge....it also handles fine at 98......in a straight line on the Interstate anyway...

On handling: Have an interstate cloverleaf not far from home, that I use as a "test pad" whenever I get another truck. The '06 GMC Z71 with Bridgstone Dueler H/Ts, went around there fairly comfy at 50MPH, maybe 45 in the rain (ramp is marked @ 25MPH, which is far too low).

The 2010 Z71 w/Bridgestone A/Ts, coil-over front suspension and Ranchos, will go around there at 55MPH and about 50 when it's wet, before the ass-end wants to kick out. Thought the A/Ts would be less bitey than the H/Ts, but they're actually stickier, especially in the rain and hydroplane less in standing water. Figuring it's a softer compound?

They don't squawk either, like the H/Ts did, when cranking the truck around the corner at the local burger drive-up window. Them H/Ts used to skeer the hell outta people when I pulled around there and barely moving. Nary a peep outta the A/Ts.

Only thing I've noted, is that the new truck has rack and pinion steering and reacts very quickly to any steering wheel movement. Gonna have to relearn pouring coffee from the thermos, on hunting trips.