What is the difference between TDi engine and CRDi engine? Does VW, Skoda TDi and Tata TDi engines have same technology? by Abhisek Swarnakar on September 1, 2012 asked in 7 answers Shreyans Jain answers: TDi means turbocharged, direct injection. CRDi means Common rail direct injection. CRDi technology is an evolution of TDi. However, TDi in VW/Skoda speak in the nomenclature for their diesel engines, all of which are turbocharged and deploy common rail technology. Similarly, Merc uses CDI, Renault uses dCI and Toyota uses the D4D name. Tata’s TDI in an aberration. It stands for turbodiesel intercooled. These are normal turbocharged intercooled engines and do not have direct injection. Tata’s equivalent of VW’s TDi is the DiCOR(direct injection common rail) series found in the Safari and Aria. Siddhartha Mishra answers: To add to what Shreyans said, only VW still calls its common rail injection engines as TDI (they call it TDI CR). Tata used to call its in-house CRDI has DiCOR earlier and now calls it CR4 (Common Rail for BS4 I guess). Also, considering the bad name the Indica / Indigo DiCOR were getting, it was smart idea to “re-package” the improved engine with a new name! Abhisek Swarnakar answers: Thank you sir for such detailed explanation. Another question: Are Tata’s CR4 engine technically similar to VW TDi and Maruti’s (Fiat) DDIS engines ? Volkswagen 1.2 L polo TDi engines have 3 cylinders where as other cars with similar cubic capacities have 4 cylinders , is there any kind of drawback or advantage behind such design? Siddhartha Mishra answers: Technically similar yes. But practically superior or equivalent, no, in my opinion. 3 cylinder engines tend to have lesser bottom end torque and smaller power bands in general as opposed to 4 cylinder engines, besides more vibrations and refinement issues. VW seems to have tackled the refinement issues, though. Shreyans Jain answers: To an extent, yes. They are all common rail engines. The CR4 in fact has better drivability that the other two and is very economical as well but looses out on refinement and outright horsepower. 3 cylinder engines are compact and cheaper to manufacture. 4 cylinder units are more expensive and complex but also are more silent and refined, plus the power delivery is a bit better. Tata’s old Dicor engines on the Indigo are not comparable to the 2.2DiCOR of the Safari/Aria. The latter gives Mahindra’s 2.2mHAWK a genuine run for its money. Abhisek Swarnakar answers: If we talk about diesel engines only(1.2L to 1.6L) ,considering better drivability, fuel economy and lesser maintenance hassles , I think it would be better to opt DDIS , CR4 , Duratorq, Hyundai CRDi engines instead of what we discussed about 3 cylinder VW TDi engines .( I think Beat Diesel is not CRDi..correct me if I am wrong). Shreyans Jain answers: Personally, I am not a fan of the 1.2 VW diesel either. Beat diesel in CRDi. Its engine is in fact based on the 1.3MJD(DDiS in Maruti language) with one cylinder less. However, this is one engine which is very silent and refined despite having only 3 cylinders. The 1.3MJD is almost universally considered to be the best small capacity diesel engine in the market today. Leave a Reply Cancel replyYou must be logged in to post a comment.