Editing Cosworth DFV (section)

===DFW===
The first variant produced from the DFV was a reduced-capacity unit for the [[Australia]] and [[New Zealand]]-based [[Tasman Series]] races of 1968–69. The changes between the DFV and DFW specification were limited to a reduced [[Stroke (engines)|stroke]], taking capacity to 2491&nbsp;cc and reducing power output from the DFV's {{cvt|420|bhp|kW PS|0}} in {{f1|1967}} to ~{{cvt|360|bhp|kW PS|0}} (after winning the [[Surfers Paradise International Raceway|Surfers Paradise]] round of the [[1968 Tasman Series]], [[Jim Clark]] told that other than lacking the top end power of the DFV, there really wasn't a big difference in performance between the DFV and DFW).<ref name="motorsport02">Robson, G. (2007) Cosworth DFV: Horses for courses. ''Motor Sport'', '''83(7)''', 44–48.</ref><ref>[https://www.youtube.com/watch?v=dpq-Va4DVD8 1968 Tasman Series Rd 5 Full Race]</ref> In Tasman Series racing, other 2.5L engines that the DFW was generally up against were the Australian made [[Repco V8]], the [[Alfa Romeo]] V8 (as seen in Alfa's [[Alfa Romeo Tipo 33|T33/2]] [[World Sportscar Championship|endurance racing]] [[Sports car racing|sports car]]), a 2.5L version of the [[BRM V8 engine]], the 2.4L [[Ferrari Dino engine|Ferrari V6]], and the older 2.5L [[Coventry Climax FPF]], the Australian versions of which were actually made under licence by Repco. On tighter tracks such as [[Wigram Airfield Circuit|Wigram]] (NZ) and [[Warwick Farm Raceway|Warwick Farm]] (AUS), there was also the smaller capacity ({{cvt|1598|cc|L|1|order=flip}}) [[Cosworth FVA]] to contend with.

The DFW is was the smallest capacity variant of the DFV that was officially produced by Cosworth. The engine was a direct replacement for its DFV parent in [[Lotus 49]]s. The small engine proved just as competitive as the larger version; and Jim Clark took four race victories in 1968, though Clark also noted after the Surfers round on a track that suited higher powered cars, the lower power of the DFW was not quite suited to the full size Lotus 49T built for Formula One (highlighting the lack of top end punch along with the heavier F1 car, for the first half of the Surfers race Clark was in a dogfight for the lead with the smaller, more nimble [[Formula 2]] chassis [[Dino 246 Tasmania|Ferrari]] of [[Chris Amon]] and its {{cvt|285|bhp|kW PS|0}} V6 engine, a scenario they would repeat when Clark beat Amon by just 0.1 seconds to win the [[1968 Australian Grand Prix]] at another noted power circuit, [[Sandown Raceway|Sandown]] in [[Melbourne]]). The DFW also saw one win for [[Piers Courage]] driving a [[Brabham BT24]] for [[Frank Williams Racing]], and two victories for [[Jochen Rindt]] in the [[1969 Tasman Series]] (Rindt had replaced Clark at [[Team Lotus|Lotus]] after the [[Scottish people|Scotsman]]'s tragic death in a Formula 2 race at [[Hockenheim]] just over a month after winning the Tasman in 1968). [[Derek Bell (racing driver)|Derek Bell]] drove a DFW version of the [[Brabham BT26]] to second place in the [[1970 New Zealand Grand Prix]], and for the 1971 Tasman Series previous champion [[Chris Amon]] drove a DFW-powered version of his current Formula One chassis, the [[March 701]], to another podium finish, but in both years the Formula One-derived engine was largely outmatched by [[Formula 5000]] entrants with their 5.0L Repco-[[Holden V8 engine|Holden]] and [[Chevrolet small-block engine (first- and second-generation)|Chevrolet]] V8's producing some {{cvt|480-500|bhp|kW PS|0}} in 1971.

After the demise of the 2.5L component of the [[Tasman Formula]] following the 1971 season, the four DFW engines were converted back to DFV specification.