Anyone tried it yet. Suddenly fuel economy is creeping up the list of things to pay attention to. My electrician got a flow thru exhaust – at first I thought it was pretty silly to do what I thought was kind of a teenager thing to a commercial vehicle. He says no, fuel economy jumps a little, pays for the change within a year. While I trust him, I’d like a sample of more than one to influence my own decisionmaking. Perhaps important to note this would be for diesel.
“If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man.” – Mark Twain
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I don't think they would ever pay off. Plus I hate the noise, and it would probably be a detriment to a companies reputation. Reminds me of a redneck when I am woken up by a loud set of pipes.
I should clarify. It's not that it doesn't have a muffler or anything. And it's no louder than a diesel is normally. It does sound a little different, but I'm not sure that someone who didn't own a diesel would even notice that.
Now, if the claim pans out, and it is 4mpg better, that saves me 25 bucks a week. That would pay for itself in 32 weeks. And that would be worth it."If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man." - Mark Twain
I seriously doubt 4 mpg.
if you get the right diesel, you don't worry about the fuel mileage. spend the extra and get the good truck you don't need to modify.
RW,
Having been involved with the automotive industry for many years .... I have learned that just about all of the magic wands for fuel mileage, power etc are basically not true. If they do help, there will be some type of unacceptable tradeoff. In this day and age, I assure you that if the manufacturer of your truck could have done anything to get even 1 mpg better economy, it would probably have been done. 4 mpg is a HUGE increase for a modern vehicle, gas or diesel. I bet that every one of us could get at least 1-2 mpg better economy by just altering our driving habits ... me included.
If it sounds too good to be true, it probably is.
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
Agree that auto engineers will do the best they can, with the restraints they have. Factory exhaust systems must be quiet, no so with aftermarket.I KNOW that a glasspack system increased my mileage by 3-4 mpg. I Mistakenly sent my teenager to the shop for a new exhaust system on the old Ranger pick-up - wanna guess which system he picked? Yup the loud one.Looking for some benefit, I measured my mileage (I know what it was for the first 200k miles) to see what the diff was - it was 4mpg around town. There are two obvious reasons for the improved mileage-
-volumetric efficiency - needing less energy to move the exhaust out of the engine.
-I keep my foot off the gas pedal because the truck is so dang loud!
One of the best ways to increase highway fuel mileage in a diesel is to slow down - if you have the patience. Running 75 vs 55 in my 6.5 Chevy longbed can drop me from about 20mpg to 17 or so (the 55 mpg test was a pretty short one as I don't have the tolerance to run 55 for too long - as my speeding tickets showed back when there was a national 55 mph speedlimit...) From the folks at the dieselpage website:
"The relationship of gearing to fuel mileage has to be the single most misunderstood aspect of the GM diesel engine. A typical 6.5TD with 3.42 gearing will produce in excess of 20 mpg at 65 mph because the engine rpm at that speed is right at the engine's torque peak of about 1800 rpm. A truck with 4.10 gearing is running at about 2250 rpm at the same speed, which typically produces about 15 mpg. A 500 rpm difference might not sound like much, but in a diesel, that's about half of the useable rpm range.
6.5TD engine rpm (4L80E automatic transmission) and typical fuel economy at 65 mph:
3.42 gearing 1880 rpm (21 mpg)
3.73 gearing 2050 rpm (17 mpg)
4.10 gearing 2250 rpm (15 mpg)"
http://www.62-65-dieselpage.com/mileage.htm (subscription required for most stuff on the site and probably for this page as well.)
depends on the motor ... and driving style.
sometimes ... back pressure is a good thing.
tried like hell to convince my mechanic buddy I needed dual exhaust on my van when I bought it ... woulda sounded better and looked cool ... he talked me out of it.
sometimes the factory is right ... sometimes they're wrong.
Jeff
Buck Construction
Artistry In Carpentry
Pittsburgh Pa