"The evolution of this model has been interesting.
In 1910 there was organised in Germany the event now famous as the Prince Henry Tour.
Having an idea of opening an agency in Germany, the Vauxhall company thought that to enter for this competitive run would be useful to them.
There were penalties for involuntary stops, as in most road trials, but there was also a speed test in which marks were awarded according to a figure of merit based upon a hypothetical relationship between car-speed and rated horse-power.
It was obvious, however, that the big engine was in the most favourable position to win in the speed test, and hence, reliability being equal, to gain the premier award.
Nevertheless, the Vauxhall people entered their 90 by 120 mm.,
engined model, doing all they knew to get the maximum power from it.
Weight also being included in the formula, a lighter chassis was designed.
Further, as the width and shape of the dashboard was virtually fixed by the regulations, a body was designed with a bulbous back to give a reasonable stream-line form, and to be consistent, the Prince Henry radiator and bonnet were adopted.
This was one of the first cases of a British car having its bonnet merging into the scuttle without an intermediate no-man's land of exposed dashboard.

"Of the three Vauxhalls which ran in the Prince Henry Tour, two got full marks for reliability, and all did about 65 miles an hour in the speed trial, which was really quite good for that engine with a four-seated body and a full complement of passengers.
So many people desired cars of this special type that in 1911 it was made a regular product of the Vauxhall works, and, during the last year or so a new style has sprung up.
In this the engine dimensions are 95 by 140 mm.,
the old bore-stroke ratio having penalised the car under many hill-climbing formulae.
All such formulae which do not involve the cubic capacity of the engine are by common acceptance considered advantageous to engines with small bore and long stroke.
The chassis follows the lines of the original Prince Henry, but has rather a longer wheel base."

H. Massac Buist, March 1914.
"The evolution of this model has been interesting. In 1910 there was organised in Germany the event now famous as the Prince Henry Tour. Having an idea of opening an agency in Germany, the Vauxhall company thought that to enter for this competitive run would be useful to them. There were penalties for involuntary stops, as in most road trials, but there was also a speed test in which marks were awarded according to a figure of merit based upon a hypothetical relationship between car-speed and rated horse-power. It was obvious, however, that the big engine was in the most favourable position to win in the speed test, and hence, reliability being equal, to gain the premier award. Nevertheless, the Vauxhall people entered their 90 by 120 mm., engined model, doing all they knew to get the maximum power from it. Weight also being included in the formula, a lighter chassis was designed. Further, as the width and shape of the dashboard was virtually fixed by the regulations, a body was designed with a bulbous back to give a reasonable stream-line form, and to be consistent, the Prince Henry radiator and bonnet were adopted. This was one of the first cases of a British car having its bonnet merging into the scuttle without an intermediate no-man's land of exposed dashboard.
"Of the three Vauxhalls which ran in the Prince Henry Tour, two got full marks for reliability, and all did about 65 miles an hour in the speed trial, which was really quite good for that engine with a four-seated body and a full complement of passengers. So many people desired cars of this special type that in 1911 it was made a regular product of the Vauxhall works, and, during the last year or so a new style has sprung up. In this the engine dimensions are 95 by 140 mm., the old bore-stroke ratio having penalised the car under many hill-climbing formulae. All such formulae which do not involve the cubic capacity of the engine are by common acceptance considered advantageous to engines with small bore and long stroke. The chassis follows the lines of the original Prince Henry, but has rather a longer wheel base."
H. Massac Buist, March 1914.
Vauxhall Prince Henry