Editing Panhard (section)

===Inter-war period===
Following the return to peace in 1918, Panhard resumed passenger car production in March 1919 with the 10HP Panhard Type X19, which used a 4-cylinder {{convert|2140|cc|abbr=on}} engine.<ref name=Automobilia1920>{{cite journal |title=Automobilia |journal=Toutes les voitures françaises 1920 (Salon [Paris, Oct] 1919) |volume=31 |pages=74|year=2004|publisher=Histoire & collections|location=Paris}}</ref> This was followed three months later by three more 4-cylinder models which will have been familiar to any customers whose memories pre-dated the [[First World War|war]], but they now incorporated upgraded electrics and a number of other modifications.<ref name=Automobilia1920 /> For the [[Paris Motor Show|15th Paris Motor Show]], in October 1919, Panhard were displaying four models, all with four cylinder engines, as follows:<ref name=Automobilia1920 />
:* Panhard Type X19 2,150 cc / 10 HP
:* Panhard Type X31 2,275 cc / 12 HP
:::''(This replaced the 12 HP Panhard Type 25 for 1920.)''
:* Panhard Type X28 3,175 cc / 16 HP
:* Panhard Type X29 4,850 cc / 20 HP

By 1925, all Panhard's cars were powered by [[Knight Engine|Knight sleeve valve]] engines that used steel [[sleeve valve|sleeves]].<ref name=Automobilia1925>{{cite journal |title=Automobilia |journal=Toutes les voitures françaises 1925 (Salon [Paris, Oct] 1924) |volume=72s |pages=74|year=2005|publisher=Histoire & collections|location=Paris }}</ref> The steel sleeves were thinner and lighter than the cast iron ones that had been fitted in Panhard sleeve valve engines since 1910, and this already gave rise to an improved friction coefficient permitting engines to run at higher speeds.<ref name=Automobilia1925 /> To reduce further the risk of engines jamming, the outer sleeves, which are less thermally stressed than the inner sleeves, were coated on their inner sides with an anti-friction material, employing a patented technique with which Panhard engineers had been working since 1923. This was one of several improvements applied by Panhard engineers to the basic [[Knight Engine|Knight]] sleeve-valve engine concept.<ref name=Automobilia1925 />

In 1925 a {{convert|4800|cc|abbr=on}} model set the world record for the fastest hour run, an average of 185.51&nbsp;km/h (115.26&nbsp;mph).

A surprise appeared on the Panhard stand at the [[Paris Motor Show|20th Paris Motor Show]] in October 1926, in the shape of the manufacturer's first six-cylinder model since before the [[First World War|war]].<ref name=Automobilia1927>{{cite journal |title=Automobilia |journal=Toutes les voitures françaises 1927 (Salon [Paris, Oct] 1926) |volume=78s |pages=74 |year=2006|publisher=Histoire & collections|location=Paris}}</ref> The new Panhard 16CV "Six" came with a 3445cc engine and sat on a {{convert|3540|mm|in|1|abbr=on}} wheelbase.<ref name=Automobilia1927 /> At the show it was priced, in bare chassis form, at 58,000 francs.<ref name=Automobilia1927 /> Of the nine models displayed for the 1927 model year, seven featured four-cylinder engines, ranging in capacity from 1480cc (10CV) to 4845cc (20CV), and in price from 31,000 francs to 75,000 francs (all in bare chassis form).<ref name=Automobilia1927 /> Also on show was an example of the 8-cylinder 6350cc (35CV) "Huit" model which Panhard had offered since 1921 and which at the 1926 show was priced by the manufacturer in bare chassis form at 99,000 francs.<ref name=Automobilia1927 />

When Panhard presented their 1931 line-up at the [[Paris Motor Show]] in October 1930, their last two four-cylinder models had been withdrawn, along with the 10CV six-cylinder Type X59.<ref name=Automobilia1931>{{cite journal |title=Automobilia |journal=Toutes les voitures françaises 1931 (Salon [Paris, Oct] 1930) |volume=90 |pages=74–76|year=2008 |publisher=Histoire & collections|location=Paris}}</ref> Instead they concentrated on their "S-series" cars, designated "[[Panhard CS]]" and "Panhard DS" according to engine size, and introduced a year earlier.<ref name=Automobilia1931 /> Publicity of the time indicated the "S" stood for "Voitures surbaissées" (cars having an "underslung" chassis,<ref>With an "underslung" chassis, the axles were placed directly above (rather than beneath) the chassis “floor”, so that the car's height and centre of gravity could be reduced.</ref>) but, clearly captivated by the power of alliteration, added that "S" also indicated cars that were "...souples, supérieures, stables, spacieuses, silencieuses, sans soupapes (i.e., using valveless cylinders)...".<ref name=Automobilia1931 /> Four of the five Panhards exhibited featured increasingly lavish and pricey 6-cylinder engined cars, their engine sizes ranging from 2.35-litres to 3.5-litres.<ref name=Automobilia1931 /> There was also an 8-cylinder {{convert|5.1|L|cid|abbr=on}} Panhard Type X67 on display, with a generous {{convert|3590|mm|in|1|abbr=on}} wheelbase and listed, even in bare chassis form, at 85,000 francs.<ref name=Automobilia1931 />

Panhard et Levassor's last pre-war car was the unusually styled monocoque [[Panhard et Levassor Dynamic|Dynamic]] series, first introduced in 1936.<ref>{{cite journal |first=René |last=Bellu |title=La Panhard Dynamic: Sa carosserie étonne et sa conception technique réserve elle aussi des surprises |trans-title=Its surprising appearance and concept still hides some surprises |language=fr |journal=Automobilia |publisher=Histoire & Collections |page=31 |location=Paris |number=7 |date=November 1996 |ref=RBaut }}</ref>

Panhard et Levassor also produced railbuses, including some for the [[metre gauge]] [[Chemin de fer du Finistère]].