# Semi-Truck speeds.... **URL:** \ **Category:** Factual Questions\ **Created:** [July 1, 2003, 2:18am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486 "2003-07-01T02:18:15Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![HPL](https://avatars.discourse-cdn.com/v4/letter/h/3da27b/32.png) [@HPL](https://boards.straightdope.com/u/HPL)\ **Post date:** [July 1, 2003, 2:18am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486/1 "2003-07-01T02:18:15Z")
I was watching _Terminator 2_ last night and noticed that everytime somebody takes over a Semi-truck it pretty much outruns anything it is chasing. Can Semi-Trucks really go that fast or was the movie bending reality a little bit? ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [July 1, 2003, 2:53am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486/2 "2003-07-01T02:53:49Z")
Think of it this way, a Semi has a very powerful engine designed to pull up to 80,000Lbs and it has lots of gears. Unloaded There is plenty of torque to make the truck accelerate quickly. It’s been a while since I saw T2, but I am sure that at least some of what you saw is movie magic. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [July 1, 2003, 3:33am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486/3 "2003-07-01T03:33:57Z")
But the tanker truck at the end was fully loaded. What kind of top speed can you expect from such a vehicle? ---
**Author:** ![Argatha](https://avatars.discourse-cdn.com/v4/letter/a/b487fb/32.png) [@Argatha](https://boards.straightdope.com/u/Argatha)\ **Post date:** [July 1, 2003, 4:56am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486/4 "2003-07-01T04:56:06Z")
Talking to some of my trucker friends, they routinely run speeds in excess of 110 MPH in places like Utah where it’s flat and the roads are straight. ---
**Author:** ![mmmiiikkkeee](https://avatars.discourse-cdn.com/v4/letter/m/edb3f5/32.png) [@mmmiiikkkeee](https://boards.straightdope.com/u/mmmiiikkkeee)\ **Post date:** [July 1, 2003, 5:22am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486/5 "2003-07-01T05:22:35Z")
Weren’t the good guys being outrun because their tiney stolen truck could only do 55mph? Most any vehicle could overtake that! Oh yeah, John’s bike was outrun by a tractor unit too… I don’t know how fast that was supposed to be going through the canal. But yes, those semis are very powerful and even though they’re not that aerodynamic, I’d say they could get up to a pretty good speed unloaded. Have you seen those events where they drag race the tractors? ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [July 1, 2003, 5:27am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486/6 "2003-07-01T05:27:43Z")
Note that the tanker at the end is chasing a little shitbox quarter ton pickup that appears to be on its last legs - not very speedy prey. If I recall correctly, the semi tractor involved in the chase earlier in the movie (when the kid’s on the dirt bike and Arnie’s on the Harley) isn’t pulling any trailer, let alone a loaded one. ---
**Author:** ![Ranger](https://avatars.discourse-cdn.com/v4/letter/r/258eb7/32.png) [@Ranger](https://boards.straightdope.com/u/Ranger)\ **Post date:** [July 1, 2003, 6:26am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486/7 "2003-07-01T06:26:55Z")
Movie Magic aside, while Semi trucks can go quite fast, a truck pulling a loaded trailer, or an empty trailer for that matter is not quick. It’ll take me longer to get up to highway speed than it’ll take a 4 wheeler. And it’ll take me more than a football field to go from 55 mph to a dead stop. ---
**Author:** ![HPL](https://avatars.discourse-cdn.com/v4/letter/h/3da27b/32.png) [@HPL](https://boards.straightdope.com/u/HPL)\ **Post date:** [July 1, 2003, 6:58am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486/8 "2003-07-01T06:58:31Z")
> [@](#): > > \*Originally posted by Gorsnak \* > \*\*Note that the tanker at the end is chasing a little shitbox quarter ton pickup that appears to be on its last legs - not very speedy prey. > > If I recall correctly, the semi tractor involved in the chase earlier in the movie (when the kid’s on the dirt bike and Arnie’s on the Harley) isn’t pulling any trailer, let alone a loaded one. \*\* Good point. John was riding a little dirtbike that probably wouldn’t be able to got more then 30 anyway, though I did find it interesting that Arnie was behind the truck for so long on that harley. It also seemed like those semis accelerated pretty quickly, or at least the one at the end did. ---
**Author:** ![whatshallIuse](https://avatars.discourse-cdn.com/v4/letter/w/9de0a6/32.png) [@whatshallIuse](https://boards.straightdope.com/u/whatshallIuse)\ **Post date:** [July 1, 2003, 8:25am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486/9 "2003-07-01T08:25:05Z")
When I was single, I drove long haul for 7 years. This included Peterbuilt’s Kenworth’s and Volvo’s (anyone interested they were 359, W900 and 770’s respectivley). Agratha, you’re friends are either having fun with you or they weren’t drinving insurable rigs. All road-legal tractors have governors for insurance reasons. The max I’ve seen was 85 mph from an independant driver. Yes, many tractors can produce upwards of 600 hp (most are 400-500 range) the gear ratio doesn’t allow for 110 mph unless fully loaded going downhill in neutral (the transmission is not able to handle that speed). But in special “pulls” and races. these rules obviously don’t apply. Hope this helps. ---
**Author:** ![Really\_Not\_All\_That\_Bright](https://avatars.discourse-cdn.com/v4/letter/r/e8c25b/32.png) [@Really\_Not\_All\_That\_Bright](https://boards.straightdope.com/u/Really_Not_All_That_Bright)\ **Post date:** [July 2, 2003, 10:29am UTC](https://boards.straightdope.com/t/semi-truck-speeds/185486/10 "2003-07-02T10:29:28Z")
John was riding a 50cc dirtbike… the fastest 50 I’ve ever seen was prepped for junior competition and pulled 45 downhill. And it isn’t that hard to disable a governor on a road car- can it be that much more difficult on a truck? I can believe that the gearing would be low enough not to allow it though.