Ok, so I have had my 1999.5 A4 1.8T (manual) for about 5 months or so. I regularly drive from SLC, UT to Las Vegas NV (which is about 420 miles). I don't have a trip computer but have figured I get about 24.5 mpg on that trip (I get about 360 miles on a 15 1/2 gallon tank before I am on empty). I am averaging about 85 miles and am using the cruise control with no AC. I would not be concerned but according to the manual and such I should be getting almost 30 on the highway.

Any thoughts on what I can do to improve the gas milage? I changed my air filter about one week ago as well as the oil (Mobil One 0w5w) and just today I changed my plugs (it was a lot easlier than I thought) without getting a CEL. I am going to Vegas tomorrow and just wanted to see what else I can do to improve the gas milage.

 

May want to try some fuel injector cleaner, I would recommend Gumout Regane. Also changing your O2 sensors will inprove fuel economy.

 

get a festiva

 

Slow down. Check tire pressures with tires cold. Don't carry heavy things you don't need. Never use a roof rack.

 

Jest , I tried Gumout Regane and mileage memained the same.

 

I used the stuff like for a month solid. It probably won't work if your injectors are clean to begin with (or not nearly as dirty as mine).

 

i heard that if your diverter valve is bad your milage will go down

 

Thanks for all your input, I will be putting in some fuel cleaner both ways and see how it goes. I need to replace my DV, and just want to know if it is something that I can do. (I feel totally comfortable changing my oil and spark plugs and air filter) If I can do this, do you think changing my DV would be in my skillset?

 

DV swap is VERY easy. Do a search of the archives, there are some pretty good instructions on how to do it posted at this forum. You can always drop me a PM if you can't find it or if you're still confused.

-T

 

Are you using 91 octane gas?
Borrow a VAG and check for codes.
Drive at 75 mph rather than 85 mph
Increase the inflation on your tires from the recommended 32 psi to about 40.