Lotus 12

{{Racing car |

|Car_name = Lotus 12

|Image = 1957 Lotus 12 Formula 2 (31515662418).jpg

|caption =

|Category = Formula One, Formula Two

|WC_results_only = Y

|Constructor = Team Lotus

| Predecessor =

| Successor = Lotus 16

|Designer = Colin Chapman

|Team = Team Lotus

| Technical ref = {{cite web|url= https://www.ultimatecarpage.com/spec/1455/Lotus-12-Climax.html |title=Ultimate Car Page Lotus 12|accessdate=2023-07-15}}

|Drivers = {{flagicon|UK}} Graham Hill
{{flagicon|UK}} Cliff Allison

|Chassis = Aluminium body on multi-tubular space frame

|Front suspension = Double wishbone, coils springs, dampers, anti-roll bar

|Rear suspension = Chapman strut, trailing arms, fixed length drive shaft

| Length = {{convert|130.9|in|cm|1|abbr=on}}

| Width = {{convert|60|in|cm|1|abbr=on}}

| Height = {{convert|35|in|cm|1|abbr=on}}

| Wheelbase = {{convert|87.9|in|cm|1|abbr=on}}

| Track = {{convert|48|in|cm|1|abbr=on}}

|Engine name = Coventry Climax FPF

|Engine position = Front engined, longitudinally-mounted

| Capacity = {{convert|1965|cc|cuin|1|abbr=on}}

| Configuration = Inline 4-cylinder, DOHC

| Turbo/NA = Naturally-aspirated

| Gearbox name = Ansdale-Mundy transaxle

| Gears = 5-speed

| Transmission type = manual

| Differential = ZF diff. with bespoke casing

| Battery =

| Power = {{convert|175|bhp|kW|1| abbr=on}}

| Torque =

| Weight = {{convert|320|kg|lb|1|abbr=on}}

| Fuel = Petrol

| Lubricants =

| Brakes = Disc, all-round

| Tyres = Dunlop|

| Clutch =

|Debut = 1958 Monaco Grand Prix

| Last_event = 1959 British Grand Prix

|Races = 9

|Wins = 0

|Cons_champ =

|Poles = 0

|Fastest_laps = 0

| Podiums = 0

}}

The Lotus 12 was a British racing car used in Formula Two and Formula One. It debuted at the 1958 Monaco Grand Prix and was Colin Chapman's first single-seat racer.

Design

Colin Chapman's first foray into single-seater racing, the 12 appeared in 1958. It featured a number of important innovations Chapman would use on later models. To better use the power of the Coventry Climax engine, it was designed, as usual, for low weight and low drag, relying on a space frame. It placed the driver as low as possible, reducing the height of transmission tunnel by way of a "conceptually brilliant" five-speed sequential-shift transaxle located in the back. This transaxle was designed by Richard Ansdale and Harry Mundy. The gearbox had a (long-undiagnosed) oil starvation problem, thus earned the nickname "Queerbox" for its unreliability.

Although the first two examples of Lotus 12 had De Dion rear suspension, it also introduced a new suspension configuration with what came to be called "Chapman struts" in the rear, essentially a MacPherson strut with a fixed length halfshaft with universal joints on the ends utilised as a suspension arm.Setright, pp. 1225–6

{{Listen

|filename =Lotus-Climax 12 (1958).ogg

|title =Lotus-Climax 12

|type =sound

|style =float:right

}}

Lotus 12 was the first Lotus to be fitted with the iconic wobbly-web wheels.{{Cite book

|title=Colin Chapman: Inside the Innovator

|last=Ludvigsen |first=Karl

|authorlink=Karl Ludvigsen

|publisher=Haynes Publishing

|year=2010

|isbn=978-1-84425-413-2

|ref={{harvid|Ludvigsen|Colin Chapman}}

|pages=119–121

}} Reflecting Chapman's emphasis on engineering for lightness, these were cast in magnesium alloy, a kind of crimped cylinder, resulting in minimum material and maximum strength, without the weaknesses induced by slots in conventional designs.Setright, p. 1225

Despite its engineering advances, the 12 was not a success in F1. In F2, the car won the class in the mixed F1/F2 1958 BRDC International Trophy, driven by Cliff Allison, but in spite of a small number of podiums, was usually drowned in a sea of Coopers.