I'm looking at changing my converter for fuel savings only. Currently the truck(92 xcab 2wd) does about 18 mpg highway empty at 65mph using a conservative technique. I drive this truck 500-1200 miles a week with occasional long 2.5 hour runs to central ks. 1/3 of the time I tow a 16' trailer with 4' sides.


Could I expect 3 mpg increase from a converter alone. Here are some projections


Stock converter or

18mpg

per mile $.21

per 40k miles $8400

savings

per 200k $41,111

savings


20 mpg

per mile .19

per 40k miles $7600

savings $800

per 200k $37000

savings $4111

22 mpg

per mile .17

per 40k miles $6800

savings $1600

per 200k $33636

savings $7475


Keep in mind 18 mpg is an extremely conservative number. My last tank driving kc to topeka round trip with about 1 hour of town mileage was 14mpg.


I'm looking for some hard numbers on fuel economy after a converter change.

 

for all intensive purposes it will improve your fuel mileage. By how much will depend on a couple things. Which converter you get, your right foot etc. etc.

A tighter converter in all likelihood would probably increase the life of the transmission itself too. A better converter makes less heat, especially while towing. Heat is probably the #1 enemy of an automatic.

I'm sorry I can't give you hard numbers to work with, but if you get a better converter, I very very seriously doubt you'll regret it.

 

Currently looking at a $650 goerend. As for right foot I can be very disciplined. Have a modified saturn SL with a best tank average of 62mpg double verified. Had a one year average of 40mpg+ mixed/city. Averaged 52mpg on 2 separate 3500 mile vacations fully loaded with 4 people and luggage.

 

also, your 18mpg isn't overly good for that truck, even for an auto. With my truck (before the transmission went on me :S) and keep in mind I have my fuel turned up too (probably have 300hp to the wheels now) with all the other mods in my sig and my truck is a 4x4, I was getting 17-18 mpg strictly hwy if I keep it around 60mph on winter fuel. Any city driving and my mileage very quickly goes below 14-15mpg but I don't drive overly nice either. I would think you should get better mileage than me.

Is your truck stock? and do you run 2 stroke oil in the fuel tank with each fillup?

I guess you'd just drive up to Goerend's shop and have them install it? It's not overly far from where you are.

 

Well, as my transmission gets more and more slippery in my dually, I watched 17-18mpg go down to 13-14mpg almost no matter how hard I tried. Best I got was a 6 hour highway trip at 50mph or so: it was only 15mpg.

I'm convinced the worse the transmission gets, the worse the mileage gets. My 89 with 75k miles or so gets 20-22mpg with 3.07s and a stock 727 transmission/converter. You should be able to get that with 3.54s and a good converter.

 

Logic says your fuel mileage would improve. HOWEVER, there are people here who have put in a tighter converter and actually gotten worse fuel mileage. I have no idea why this would happen, but do a search on it.

 

my milage didnt improve with a new converter .in the city

if you get a tight converter you need to fuel your turbo huge to get it to spool.even with my quick spooling he351.from idle at a stop light to truck moving and turbo starting to spool is actually harder now.there is a delay.do when i take off from a light the truck smokes like a train.
if your going for performance do the converter.
if your going for milage

LEAVE IT STOCK

my truck got 400+miles per 20 gal stock with 4:10 gears stock small tires

now gets 13mpg mods in the sig

 

Yours was the story I had in mind when I posted that, Lucas.

 

I think if your convertor is too tight, you won't be able to spool your turbo right. Something like that anyways.

Edit: Did not see Lucas' post. What he said.

 

Head, how does your Suncoast do with that S362? I hear their non-lockup TC's are pretty tight.

 

It does good but something is up with my transmission, it shifts up way to early.

 

with the tcs converter and the new trans I picked up 2mpg, but ive only run thru two tanks of fuel since trans re build and dont no wether the increase in milage is due to new trans or the converter.

 

Check your TV cable adjustment (so as to make it shift a little later).

 

a new trans and converter will give you milage on the hiway....
after the truck is moving.
if your trans is slipping ....no matter what you do your milage will suck

asuming your trans is "tight" and what converter you get....your milage will improve
but its my opinion why spend money on a slightly better converter???

a new trans with slightly upgraded not to tight converter is the best for milage but unless you have money to burn dont bother.

id look at electic fans, lowering, no a/c ,etc .and all that crap too if your so worried about milage.

 

It seems, a tighter converter often means a converter that's better aligned with the given engine's torque peak. Hence, an increase in apparent power to the ground and better fuel efficiency.