Fuel Additives

Thomas M · Post by **Thomas M** » Tue Aug 25, 2009 6:52 pm

1991 Jetta non-turbo diesel, 247,000 miles.

I am the original owner and only driver of this car. I have never put anything in the fuel tank except diesel. Should I start now? Is it good preventative maintenance to add to the fuel as the engine may be reaching middle age?

I can nudge, I mean really nudge it up to about 48mpg.....may a hair more. I am burning minimal oil and except for the normal diesel rattling the car runs fine. Why would I now put an additive into the fuel?? Are there good reasons to start spiking my fuel??? Would it help the injectors or pump with this many miles???

Comments are welcome and appreciated.

82vdub · Post by **82vdub** » Tue Aug 25, 2009 7:35 pm

When your car was made, diesel fuel had 2000 parts per million (PPM) of sulfer in the fuel. Sulfer is a lubricant. In the mid-late 90's, this was dropped to 500 PPM, and starting in 2007 it dropped to 15ppm. The IP in your car was not designed to run on 15PPM fuel, but manufacturers are supposed to add additive to the fuels to bring up lubrication properties.

I run a mixture of wax, 30W non-detergent oil, and Stanadyne fuel additive to each tank of fuel in the summer. In the winter, I skip the wax part, but add oil and Stanadyne fuel conditioner to the fuel. It's designed to clean the fuel system and raise the lubrication properties. I would at least add fuel conditioner to the fuel system a few times a year, at a minimum.

odie · Post by **odie** » Wed Aug 26, 2009 9:53 am

a small amount of oil probably can't hurt.

I'd suggest either 2-stroke oil, ATF, vegetable/cooking oil, Power Services stuff, or even some engine oil.

everyone has their own favorite snake oil. maybe i'll blend it all and make a cocktail, lol.

probably a cup or less per tankfull is all you need. I just kinda WAG it.

I've been using PS products. but only when i remember to add it. I think I'm gonna switch to some kind oil when my bottle is empty.

VWCaddy · Post by **VWCaddy** » Wed Aug 26, 2009 11:27 am

I run a mix of Stanadyne and 2-stroke oil in mine, details below:
- http://www.4crawler.com/VWpickup.shtml#Vehicle

odie · Post by **odie** » Wed Aug 26, 2009 1:44 pm

so you are the project caddy shack dude. I've had that link in my favorites "vw" folder for 2 or 3 years.

Ira B · Post by **Ira B** » Wed Aug 26, 2009 10:16 pm

VWCaddy wrote:I run a mix of Stanadyne and 2-stroke oil in mine, details below:
- http://www.4crawler.com/VWpickup.shtml#Vehicle

Just read through your site the other day.
GREAT STUFF!!

Ira B · Post by **Ira B** » Sun Aug 30, 2009 11:14 am

Due to reports of reduced lubrocity of ULSD I have been adding 1/2 qt. of non-detergent 30w oil to each tank of dino fuel and am considering whipping up a pre-mix of 30w, diesel and wax.
Any suggestions as to mix ratios?

MPalm · Post by **MPalm** » Sun Aug 30, 2009 1:04 pm

82vdub wrote:When your car was made, diesel fuel had 2000 parts per million (PPM) of sulfer in the fuel. Sulfer is a lubricant. In the mid-late 90's, this was dropped to 500 PPM, and starting in 2007 it dropped to 15ppm. The IP in your car was not designed to run on 15PPM fuel, but manufacturers are supposed to add additive to the fuels to bring up lubrication properties.

I run a mixture of wax, 30W non-detergent oil, and Stanadyne fuel additive to each tank of fuel in the summer. In the winter, I skip the wax part, but add oil and Stanadyne fuel conditioner to the fuel. It's designed to clean the fuel system and raise the lubrication properties. I would at least add fuel conditioner to the fuel system a few times a year, at a minimum.

It is a european car and the european diesel has had 5-30 PPM since early 90's. I guess that the IP's are made to german spec even if the car is assembled elsewhere?
With that said, yes you should use something to that increases lubrication since the ULSD you have over there doesn't meet the lubrication specs set by Bosch.
I would use 2-stroke oil.

Post by **Fatmobile** » Mon Aug 31, 2009 12:03 am

An oil that is meant to burn like 2-stroke oil is often ashless.
Wax is ashless.
Ashes causes wear.

Thomas M · Post by **Thomas M** » Sat Sep 05, 2009 4:38 pm

What is this "wax" that some add to the fuel??

82vdub · Post by **82vdub** » Mon Sep 07, 2009 5:39 pm

Regular parafin "candle" wax that's dissolved in fuel and added to the tank of fuel. Not sure how cold it gets in Vancouver or where you take your car, but make sure you do your own testing on amount of wax added to fuel before you run the car in cold temps. Could solidify and cause headaches for you.

Bormie · Post by **Bormie** » Tue Sep 08, 2009 10:07 pm

I run 2oz Redline Diesel fuel catalyst per tank. Usually about 8-9 gal at fill up.
I have been getting 48-51mpg driving 65-70mph.
The injection pump was rebuilt with the new type seals back when the government reduced the sulfur the first time back in '93 or '94. The P/O had the State cover the cost.
Pump is advanced 1mm. Simple redneck cold intake hose installed a couple weeks ago. Before that I could never break 50mpg commuting to work. Light port cleanup job and gasket match at overhaul. K&N filter. FN Trans. 40psi in 195-60-14 tires. Odometer checked with GPS.

Thomas M · Post by **Thomas M** » Wed Sep 09, 2009 12:23 pm

Bormie,

What is the "Simple redneck cold intake hose"??????

General Question: As I understand, Automatic transmission fluid is used as a cleaner. However, I don't think it is designed to burn and therefore leaves and ash which could be dertrimental to the system. I was warned about this by a diesel tech.
Is it ok to use the ATF once in a while and a little at a time or should one invest a a commerical injector type cleaner?????

Bormie · Post by **Bormie** » Thu Sep 10, 2009 9:18 am

The redneck cold air intake is just a piece of molded 2in hose about 1 1/2 ft long with a slight bend that I clamped onto the stock plastic intake that puts the inlet between the fender and frame away from the top of the engine. I think vw changed the design in 85 to intake from the inner fender.

odie · Post by **odie** » Thu Sep 10, 2009 12:23 pm

sounds pretty nifty. cold fresh air is always good.