Computer chip conversion for VW Passat to regular gas?

[old mark]

Is there some way to get a '99 Passat to run on regular gas? A chip that can be installed, tuning, etc? It is a nice car to drive, but the $4.15 gas is starting to cramp my driving. Thanks.

mark

[jimmil]

1. Is this the turbo wagon?

Just shooting from the hip here having worked performing engine management if it is the turbo I would not recommend going to regular gas. I am still trying to find out the specs for the car. What is the compression ratio? The higher the ratio the more prone to knock you will have when you load the engine up. Acceleration in a high gear from a low speed is the absolute worst thing you can do.

A little more information if you please and I will try and find some too.

[jimmil]

2. More information....

Regardless whether you have the 1.8T or the VR6 engine the engine requires premium due to high compression. Putting in 89 or 87 will lower the MPG due to the computer retarding the timing. When you retard the timing what happens in the engine is the spark ignites at a less than optimal degree. Remember, adding octane does not increase the energy in gasoline, it only changes the flash point (effecting the 90/10 wave front propagation) of the gas so that it will not auto ignite when subjected to higher compression (which is actually adding more heat as the mixture compresses). If it does auto ignite you have knock so the computer retards the timing so that the spark occurs when the piston is lower (less compression so less heat built up) in the cylinder. So when you have a high compression motor and you use lower octane gas not only are you getting less performance and less MPG you are causing creosote to form in the cylinders further reducing performance and causing more wear. You are causing the most expensive part of your car to wear quicker.

All that being said, in winter you may be able to get away with using a lower octane gasoline if you drive keeping the RPMs up (remember that low RPM and high gearing load an engine meaning it is working harder) and not putting your foot in it. In summer I would always use the higher octane.

[old mark]

3. Thanks...it's the 4 cyl

It belonged to my late Mother-in-law, and we inherited it. She always used regular gas, and complained bitterly about the car's poor performance. The first time I opened the gas port I saw the "93 octane" sticker. The car runs very well on premium as it was supposed to, and is a good driving car-handles well, comfortable, lots of odd german features/accessories, and my wife will be using it mainly in town.
Gets around 23 mpg which used to be pretty good.
I'm going back to my old Hyundai Elantra 5 speed-it will burn nearly anything better for longer trips.

Thanks again for your help.

mark

[jimmil]

4. Just as a precautionary tip,

For the next few fill ups I would add a bottle (or whatever the directions say) of either Techron or Red Line fuel injector cleaner and then run the piss out of it. Both of these cleaners are a detergent based and will not harm the windings of a fuel injectors as will virtually all the others. This will go a long way to cleaning the engine out and make the car perform better in the future.

[old mark]

5. Great tip:

I usually run a bottle through each car twice a year, just to keep the injectors clean. Will do both of them-they both just got oil changes and inspections in June, so now is a good time.

Thanks for the help.

mark