New exhaust system for better fuel economy

[df909]

Hi guys-

I have a 2002 Dodge Dakota with the 4.7L in it. I have the stock exhaust system with the exhaust running to one catalytic convertor and through one pipe to one muffler. If I install a second catalytic convertor and a second pipe to a second muffler, will I gain much in increased MPGs?

So, I'd essentially have two exhaust systems...one catalytic convertor and one muffler for each side. I figure it'd be a lot less resistance so I'd get maybe 5%-10% better mileage. What do you think? Thanks.

 

[kenmyfam]

Re: New exhaust system for better fuel economy

Personally I very much doubt it.

 

[dolluper]

Re: New exhaust system for better fuel economy

The cost would not make it worth any saving in fuel economy....reprograming cat,pipes,muffler,O2 sensor,wiring....oh humm more to do also...keep it simple or buy one already done

 

[mxfever]

Re: New exhaust system for better fuel economy

You have to figure the cost. Would adding a second cat that normally carries a high price tag, another muffler, plus pipe and labor offset the increase (if any) in mileage? I highly doubt it. All street V8's that I know of need a crossover to tie all cylinders together for the best performance.

 

[dockwrecker]

Re: New exhaust system for better fuel economy

Yeah definitely the crossover pipe if you do it. Everyone seems to forget that a motor fires one cylinder at a time from opposing banks. The crossover helps maintain flow as the exhaust gas cools traveling down the pipe.

 

[MTboatguy]

Re: New exhaust system for better fuel economy

Get a hold of K&N, my Dad put a complete new system on his truck, 1999 Chevy as well as air filter power induction made by them and his mileage has improved a whole bunch...but take into account, you looking at least a grand to do it, I know he paid over $1200 to get the parts and have it installed on his truck. One benefit though is not only a increase in mileage it also has quite a bit more power.

Living in S. Cali, you might also run into problems with the CARB restrictions as well

Dave

 

[Boomyal]

Re: New exhaust system for better fuel economy

I seriously doubt any improvement in gas mileage. You will probably see an increase in performance, though. Especially if you check your air intake for any restrictive areas.

I installed a full Banks header system on my 94 454 Suburban. The system included headers, muffler, tailpipe and opened up cold air intake with a K&N filter. I added a high flow cat to the lot.

It really woke that beast up. Instead of going flat by 3000 rpm, that motor now pulls strong all the way up to redline. It also sounds gnarly and mean.

.....but....it didn't do squat for the p*** poor mileage.

 

[Gary H NC]

Re: New exhaust system for better fuel economy

I seriously doubt any improvement in gas mileage. You will probably see an increase in performance, though. Especially if you check your air intake for any restrictive areas.

I installed a full Banks header system on my 94 454 Suburban. The system included headers, muffler, tailpipe and opened up cold air intake with a K&N filter. I added a high flow cat to the lot.

It really woke that beast up. Instead of going flat by 3000 rpm, that motor now pulls strong all the way up to redline. It also sounds gnarly and mean.

.....but....it didn't do squat for the p*** poor mileage.

Did the same to my Tahoe, Full custom duals with cross over and high flow cats,K&N cold air intake system and a Super Chips tuner.
Sounds really mean and tows like a beast.No more rev limiter or speed limiter but have to run 93 octane.
As far as fuel mileage...no better.

 

[642mx]

Re: New exhaust system for better fuel economy

There is only one Dodge made that gets good gas mileage, and it doesn't use spark plugs.

As far as exhaust goes, I picked up maybe 1 mpg in my 5.7L Tundra when I put a Gibson Cat-Back system on it. And the gained 1 mpg was probably due to the weight difference between the 2 systems (that factory stuff was heavy!!).

Your best bet for getting improved mileage is to check the air in your tires, keep your air filter clean, replace the plugs at recommended intervals, and use synthetic lubricants in the engine and differentials.

 

[df909]

Re: New exhaust system for better fuel economy

Hmmm...so much for that idea. I did put in a K&N filter that made a good difference & I keep the tires, plugs, & oil in good condition. I haven't thought about a chip though, would that help much?

 

[642mx]

Re: New exhaust system for better fuel economy

I'm not a big fan of chips... not on gassers anyway.