How does a convertor affect gas mpg??
Thread Starter
Teching In
Joined: Nov 2005
Posts: 22
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From: Eagle WI
How does a convertor affect gas mpg?? My friend has a 98 TA stock a4 and wants to make it faster with a 3,500 stall but is worried about the negative effects it may have on gas mpg. The car is daily driven 40 miles round trip. What can you say from experience??? Thanks!!!!!!!!
City driving might be affected a few MPG's, but highway won't change at all if it's locking up properly. I have a PT4400 and I noticed a drop, but with all my mods I still get ~14 in the city and ~24 on the highway.
As long as you've got a converter that locks up, the highway milage shouldn't change. I, on the other hand, do not. I've got a TH400 (3-speed) with an ATI 4k stall converter. It never locks up. Put that in with 4.11 gears and a spool.....and maybe I get about 15-16 mpg highway. It's turning about 4500 rpm's at 65 miles per hour. Not to mention that when I get into parking lots, the spool and converter work together to suck down the gas.
The purpose of a high stall converter is to stall higher, so it basically slips in the lower RPM's. When the factory converter would be moving the car, a high stall converter is slipping, thus wasting the power and decreasing gas millage. But that is a trade off that most are willing to make because it makes the car faster. The high stall converter puts the car is in it's power band. When you get on the highway the lock up clutch should come on and make the converter 100% efficient and act the same as the factory converter.
Chris
Chris
Currently I have a Vig 3600 and 3.73 gear in my car. I average about 16-17 mpg on my daily commute to and from work. That is 25 miles a day most of that is mostly driving in stop and go traffic with only a couple miles driving on the highway. Pure highway driving with the 3.73 I get around 25 mpg. That is stock internal car with just bolt on's and some weight removal from it. I used to get closer to 20 mpg on the drive to and from work when it was stock converter with 2.73's.
