From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Autocar magazine road test and performance data sheet for a 25 HP 3 1/2-Litre S.S. Jaguar Saloon.
| Identifier | ExFiles\Box 126\5\ scan0117 | |
| Date | 28th April 1939 | |
| April 28th, 1939. The Autocar 709 The AUTOCAR ROAD TESTS No. 1,273.—25 h.p. 3 1/2-LITRE S.S. JAGUAR SALOON Somewhere around 60 m.p.h. is reached almost automatically on sufficiently clear roads, and between 60 and 70 is the natural maintainable pace. On a journey the 3 1/2-litre Jaguar displays the highly valuable faculty of putting up nearly as good an average when no conscious effort is made to hurry as on an occasion when the driver definitely sets out to make the best use of every open stretch of road. It can be driven with little use of the gear box in average country, top being put in within a few yards of moving off from rest, and the normal kind of hill being stormed, if desired, without a change down. Alternatively, most effective use can be made of second and third to give fierce acceleration or rapid climbing of the steeper variety of hill. SINCE the introduction of the Jaguar models some two years ago the S.S. has been an outstanding make from the point of view of performance in relation to price, also a car of unusually pleasing appearance. It embodies features of refinement in the coachwork that denote a close application on the part of the manufacturers. The 3 1/2-litre size of engine provided in this biggest model of the three types offered is not used to carry the largest possible body, but instead to make a medium-sized car overall, which can be geared reasonably high for ease of running, and at the same time afford exceptional acceleration. With certain points of difference, it is of the same design as the successful 20 h.p. 2 1/2-litre model. It is decidedly in the category of a "driver's car," for there is that ready response to the throttle pedal to satisfy anyone who likes to send the speedometer needle soaring on main roads, and it handles well, too. Even on a run of the 300-mile category it is hardly possible to force it in this country, for maximum revs are 4,500 to about 4,800, giving rather more than 90 m.p.h., and this range of engine speed is usable comfortably on top gear. For example, from the customary 40 m.p.h. commencing speed the main part of the 1 in 6 1/4 gradient frequently employed for comparative purposes was taken on top gear, the minimum being about 28 m.p.h. This same hill could have been rushed if third had been engaged. The six-cylinder overhead-valve engine is quiet both mechanically and as regards exhaust. Twin tail pipes are fitted. As often applies nowadays, wind noise is more evident than mechanical noise at the higher speeds. The engine is delightfully smooth at all normally used speeds, silkily so, indeed, during leisurely driving. Nor does it become rough when driven faster, though there is a slight passing noise period, unaccompanied by vibration, at about 3,000 r.p.m., which is 60 m.p.h. on top gear. While maximum speed was being timed the highest speedometer reading shown was a full 90, at a rev counter reading of nearly 4,800 r.p.m. The instrument on the car tested read slightly above 1 m.p.h. slow from 20 right up to 80—an unusual state of affairs. DATA FOR THE DRIVER 25 H.P. 3 1/2-LITRE S.S. JAGUAR SALOON. PRICE, with four-door four-light saloon body, £445. Tax, £18 15s. RATING: 25.01 h.p., six cylinders, o.h.v., 82 x 110 mm., 3,486 c.c. WEIGHT, without passengers, 32 cwt. 3 qr. 20 lb. LB. PER C.C.: 1.06. TYRE SIZE: 5.50 x 18in. on knock-off wire wheels. LIGHTING SET: 12-volt. Automatic voltage control. TANK CAPACITY: 14 gallons; approx. normal fuel consumption, 16-18 m.p.g. TURNING CIRCLE: (L. and R.{Sir Henry Royce}): 38ft. GROUND CLEARANCE: 6in. ACCELERATION Overall gear ratios. From steady m.p.h. of 10 to 30, 20 to 40, 30 to 50 4.25 to 1, 8.0 sec., 8.1 sec., 8.7 sec. 5.19 to 1, 6.2 sec., 6.9 sec., 7.6 sec. 7.90 to 1, 4.4 sec., 4.8 sec., 5.8 sec. 13.45 to 1 From rest to 30 m.p.h. through gears ... 4.7 sec. To 50 m.p.h. through gears ... 9.8 sec. To 60 m.p.h. through gears ... 14.4 sec. To 70 m.p.h. through gears ... 19.8 sec. 25 yards of 1 in 5 gradient from rest ... 4.7 sec. SPEED m.p.h. Mean maximum timed speed over 1 mile ... 88.24 Best timed speed over 1/4 mile ... 90.91 Speeds attainable on indirect gears (normal and maximum):- 1st ... 21—27 2nd ... 36—50 3rd ... 60—77 Speed from rest up 1 in 5 Test Hill (on 1st and 2nd gears) ... 23.09 BRAKE TEST: Mean stopping distance from 30 m.p.h. (dry concrete), 31.5ft. WEATHER: Dry, cold, dull; wind fresh, N. Barometer: 29.90in. Performance figures for acceleration and maximum speed are the means of several runs in opposite directions, with two up. (Latest model described in "The Autocar" of July 8th, 1938.) Dashboard Diagram Labels: Throttle, Wiper, Ignition, Lights, Starter, Panel Light, Interior Lights, Indicators (Self Cancelling), Wiper, Ignition, Horn, Anti Dazzle, Foglights. Gearbox Diagram: R LIFT, 1, 2, 3, 4. A 47 | ||