Nitrogen Enriched Gasolines – What Are They and What Do They Do

Nitrogen Enriched Gasolines – What Are They and What Do They Do

Shell Oil has recently begun advertising their Shell V-Power “Nitrogen Enriched” Gasoline.

Why would nitrogen improve the cleaning performance of gasoline detergent?

Here are some facts to consider:

1. The earth’s atmosphere is approximately 78% nitrogen
2. Nitrogen is an inert gas that is not combustible
3. Nitrogen atoms are larger than oxygen atoms
4. Nitrogen when combusted with fuel and Oxygen creates Nitrogen Oxides (NOx)
5. NOx when combined with Volatile Organic Compounds (VOC’s) creates petrochemical smog.

Shell claims that fusing (their term) nitrogen with their detergent creates a more stable, longer lasting detergent that will be more effective in preventing gunk (their term) deposits (my term) from building up on the valves and other combustion chamber areas.

It would seem to me that adding Nitrogen will make the combustion process less efficient and could possibly lower combustion temperatures. This would seem to be the opposite of the desired effect.

It would also seem that adding Nitrogen could raise the NOx emissions from the engine which would tend to increase smog production, again the opposite of the desired effect.

I definitely applaud the idea of raising detergent levels in all gasolines. This is a quick and inexpensive way to reduce emissions and improve fuel economy.

The whole Nitrogen thing is nothing other than another marketing ploy. Shell and many other refiners have attempted to convince the consumer that they are doing something unique and wonderful, when in reality they simply want to sell more and or charge more than their competitors.

Shell needs fewer “Cutesy” TV commercials and more science, or at least they should provide some documentation to support thier claims.

If you want to do the best thing for your gasoline powered vehicle, look for fuels containing “Top Tier” fuel additives used at the manufactures “Top Tier” levels or simply purchase and regularly use aftermarket “tank additives” that meet or exceed the “Top Tier’ requirements.

This together with proper maintenance will ensure peak performance and minimum emissions from your engine.

Please let me know what you think, post your comments, ideas, and suggestions here.

Diesel Doctor

Copyright 2009 – William Richards

Diesel Fuel Mileage Decrease in Winter

Why Diesel Fuel Economy Drops in the Winter

Diesel fuel, particularly in the northern tier states changes rather significantly from season to season. In the cold weather months generally starting in September or October refiners begin to alter the chemical composition of diesel fuels to improve cold weather operability characteristics to meet ASTM, Pipeline Operator, and Customer requirements and specifications.

Refiners talk about the components that come out of the refining process as “streams”. In a typical refinery today there can be over 180 “streams” coming from the refining of crude oil. The addition of lighter product streams are known by names such as “aromatic chemicals”, “naptha’s”,” kerosene’s” and others to #2 diesel (whether Ultra-Low Sulfur Diesel (S-15) or Low Sulfur Diesel (S-500)) will lower (improve) the Cloud Point (CP), Cold Filter Plug Point (CFPP) commonly referred to as the gel point, and Pour Point (PP) depending on how much of those components are added to the base fuel. Refiners have a lot of latitude in determining how much of and what components are used to make these improvements.

The issue from a fleet operators standpoint is that these changes lower energy (Btu) content of the fuel. It is normal for fuel economy to decrease from one to as much as five percent seasonally. This decrease can be further exacerbated by fuel racks and or distributors further cutting with kerosene to try and improve cold weather operability. The normal energy content of #2 ULSD ranges between 138,000 and 140,000 Btu’s, kerosene is much lower ranging between 130,000 and 135,000 Btu’s, whereas gasoline is about 124,000 Btu’s per gallon.

As you can see the more lighter components added to fuel, the lower the energy content. Note: ULSD has 1%-3% lower Btu content than the LSD. This is primarily due to reduction in wax content in ULSD.

So if you put all of this together in a time line, you can see that you begin using additive to improve cold weather performance at the same time the refiners are blending the fuel in a way that reduces Btu content which lowers your fuel economy, then in the spring you stop using additive at the same time the refiners are going to a “summer” blend which increases the Btu content and so your mileage goes up.

Other cold weather considerations are more idle time, slower transit speeds, more time in traffic, and even driving through snow all, of which can have a significant negative impact on fuel usage.