PSD vs IDI fuel economy

nelstomlinson

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My IDI is rated at 185hp, my powersmoke at 225hp. I drive like an old man in either, so I'm not usually using the extra fuel the powersmoke turbo allows over the NA IDI.

All the fancy computer stuff is all about emissions, as someone else said.
 

Rusgo

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Yeah I agree, peak HP doesnt mean much in relation to economy if you never ask the engine for it.

Before I installed the turbo, I couldn't get worse than 16mpg if I tried. Best ever was 19mpg. It was so slow, and my Ip was so old, it made me drive like a grandma. Post turbo and fuel system refresh, grandpa mpg is still the same, but if I get into it all the time, mileage drops fast.

Though most people use the power if they have it. Goes along way to explain why people dont get better economy with modern engines in general.

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Kevin 007

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Yeah new trucks use the same amount of fuel with 3x the power for the same fuel burnt.
The overall cost of ownership long-term however....is significantly higher with newer trucks tho with massive repair bills every time the check engine light comes on. And we'll see if they are even still running in 30+ years like our idi's. I doubt it
 

ttman4

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Well whatever guys. Not been contesting any PS's lately, & I know this thread is us vs them. LOL

All I know is that when Bessie was newer she used to get 18-22 all the time.
She's in my sig.....'90 DRW, CC, 7.3 IDIT turboed, ZF5, 4.10

I had her turboed with a ATS 088 kit when she had about 300 miles on her, & they turned up the pump.....then of course I had to turn it up some more when I got home. LOL Put lots & lots& lots of miles on her & she used to get 18-22, sometimes 23. Pulled lots of really big, stupid a** big loads with her & she'd get 13-14 loaded.
She'd get 80-100K miles on pump & injectors & milage be down to about 12-13-14 empty. Pull Pump & inj & have them rebuilt & milage be back up 18-22 empty again.

Now with this '94 factory IDIT I got in her now she does good to get 13. Blow smoke & Runs & pulls awesome. Does it like a scalded dog chashed by a stripped ape.....at 13mpg!!! However fuel ain't what it was 20-30-40 yr ago either.

Got to get with Russ & get some injectors!!! Just been so busy & sidetracked it's plain unreal.... that's another story tho.
 

Chief

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However fuel ain't what it was 20-30-40 yr ago either.

I think you’re on to something here. The ULS diesel has less lubricating properties that can be harmful to our fuel systems. But does it affect fuel mileage to? We can put additives in that will bring up the lubricating properties but does it really perform as well as the LS diesel our trucks were meant to run on?
 

MtnHaul

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In regards to fuel quality I recall reading, somewhere?, that the process of removing sulfur also removes the lubricity and lowers the cetane rating. I also recall that US diesel tends to have a lower cetane rating than diesel in some foreign markets. IF higher cetane ratings contribute to higher MPGs then I'm all but sure the oil refineries here would prefer a lower rating in the interest of selling a bit more product. Call me cynical if you like.
 

Cubey

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In regards to fuel quality I recall reading, somewhere?, that the process of removing sulfur also removes the lubricity and lowers the cetane rating. I also recall that US diesel tends to have a lower cetane rating than diesel in some foreign markets. IF higher cetane ratings contribute to higher MPGs then I'm all but sure the oil refineries here would prefer a lower rating in the interest of selling a bit more product. Call me cynical if you like.

Some diesel additives claim to increase cetane rating, in addition to adding lubricity. How much it helps, I don't know.

This is what I have been using for most of the past 2000 miles in the motorhome because it sat so much and I wanted to clean up the IP and injectors: https://www.howeslube.com/products/meaner-power-kleaner

It doesn't claim to add cetane, but it claims to clean injectors and adds lubricity.

I may switch back to buying Power Service Diesel Kleen though, since it does both of those plus claims cetane boost. PS costs more per dose but eh. I used PS in the truck except last winter some when I was using Howes for antigel.

Since we pretty much NEED to use an additive to help with lubrication, we may as well use something that claims to boost cetane too when we don't need antigel.

I don't think antigel is worth bothering with for me most of the time. I think only once did I see my fuel gel any and that was a couple years ago when it got down to around 7 degrees one morning. I had antigel in it and I never had a problem starting the truck. It has a clear plastic fuel filter just before the tiny electric fuel pump and it looked cloudy when it got down that cold.

Usually I don't see temps that low though. I have been sticking around the Texas area of the country in winter.
 

79jasper

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Some diesel additives claim to increase cetane rating, in addition to adding lubricity. How much it helps, I don't know.

This is what I have been using for most of the past 2000 miles in the motorhome because it sat so much and I wanted to clean up the IP and injectors: https://www.howeslube.com/products/meaner-power-kleaner

It doesn't claim to add cetane, but it claims to clean injectors and adds lubricity.

I may switch back to buying Power Service Diesel Kleen though, since it does both of those plus claims cetane boost. PS costs more per dose but eh. I used PS in the truck except last winter some when I was using Howes for antigel.

Since we pretty much NEED to use an additive to help with lubrication, we may as well use something that claims to boost cetane too when we don't need antigel.

I don't think antigel is worth bothering with for me most of the time. I think only once did I see my fuel gel any and that was a couple years ago when it got down to around 7 degrees one morning. I had antigel in it and I never had a problem starting the truck. It has a clear plastic fuel filter just before the tiny electric fuel pump and it looked cloudy when it got down that cold.

Usually I don't see temps that low though. I have been sticking around the Texas area of the country in winter.
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Sure, it's not fully scientific, but enough for me to avoid some.

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Cubey

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Sure, it's not fully scientific, but enough for me to avoid some.

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Well, the PS 911 is just meant to unfreeze in an emergency, not do much more. Too bad the PS grey bottle wasn't tested too. The Hot Shots stuff is pretty expensive, but in his "tests" it was one of the best.

Howes anigel did the worst for lubricity? I guess that's why it's the cheapest. I guess I will stick to Power Service stuff.
 

Rusgo

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If you count all the comments as peer review...definitely science. I'm convinced. Just used hotshots for the first time last month. Saw it on amazon randomly. Wasn't expecting anything so wasn't even paying attention. Over the next few days I kept thinking how much smoother the engine runs and pulls. Less clacking too. Then realized it was the hotshots.

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