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If your lorrys weren't restricted to 60mph, how fast do you reckon they could go?
Just wondering.
It's 110kph here in Oz on the open roads so 68mph not an issue for some sizeable trucks.
119.77mph
My last unrestricted 7.5 ton would sit at 80 all day long and believe it or not I have been over taken by an articulated Irish wagon hurtling down Shap like I was standing still.
How big is the hill?
"mikewsmith - Member
It's 110kph here in Oz on the open roads"
have recently moved to Oz I reckon that's a minimum not maximum 😯
I was once sitting at about 75-80 on the continent and was overtaken by a Mclaren/Mercedes F1 truck, didn't seem to pass slowly either. Always wondered if it had been tinkered with!
Region of 100. See the old truck episode of top gear for why you dont want trucks going that fast.
As trucks are designed, not a lot faster.
For maximum fuel efficiency, the gear ratios will be chosen so that it's in the upper middle of the green band, say 1500rpm, at 90km/h.
With a red line at, say 2200rpm, that gives a top speed of 132km/h or about 82mph.
[i]If[/i] you were somehow able to alter the gearing though...
Most 44 tonners are somewhere between 400 - 500 bhp.
An unladen artic, tractor & trailer, is round about 14 tonnes.
So that's around 32bhp per tonne.
Not a lot by car standards, so I'm not convinced it would be much faster, taking in to account the increased wind resistance and tyre drag over a car.
Short answer;
A fully loaded truck with an old manual box that can be knocked in to neutral down a steep hill will go a lot faster than a non speed limited empty truck ever will on the flat. Probably.
My dad used to drive a Seddon Atkinson artic full of bread, so nowhere near max weight. Could easily manage 85mph downhill, 80mph on the flat (before restrictors were brought in).