# Diesels and Urea
**URL:** https://boards.straightdope.com/t/diesels-and-urea/466813
**Category:** Factual Questions
**Created:** [October 7, 2008, 5:37am UTC](https://boards.straightdope.com/t/diesels-and-urea/466813 "2008-10-07T05:37:25Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)
#### Post date: [October 7, 2008, 5:37am UTC](https://boards.straightdope.com/t/diesels-and-urea/466813/1 "2008-10-07T05:37:25Z")
Lately I’ve been hearing about Blutech (sp?)…apparently injecting urea into the exhaust manifold cleans up the smell and particulates.
How?
Aren’t diesel catalytic converters available and do a good enough job?
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### Author:  [@Dog80](https://boards.straightdope.com/u/Dog80)
#### Post date: [October 7, 2008, 6:28am UTC](https://boards.straightdope.com/t/diesels-and-urea/466813/2 "2008-10-07T06:28:13Z")
There are two main technologies in diesel cars and trucks. The urea method (urea solution is sold under the market name [AdBlue](http://en.wikipedia.org/wiki/AdBlue) in Europe)is called [Selective Catalytic Reduction (SCR)](http://en.wikipedia.org/wiki/Selective_catalytic_reduction)
The other technology is called [Exhaust gas recirculation (EGR)](http://en.wikipedia.org/wiki/Exhaust_gas_recirculation).
I am not following this too closely, but both technologies have their pros and cons. At present [Scania uses EGR in their trucks](http://www.scania.com/products/bus/technology/EGR/) while most other mfgs. use SCR technology