11% FE improvement with diesel fuel additive

[ToddT58]

I did a test using Power Services white bottle cetane boost additive. On a 1,000 mile trip, I alternated tanks with and without. The fuel economy consistently increased from 18.5 to over 20mpg when running the additive and back down when not. I'll use the silver bottle now that warm temps are here.

That was in my F-250 7.3 Powerstroke, 3.73 rear end, 2wd, singe rear wheel.

I'm currently running a test on my '82 VW Rabbit diesel 1.6/ 5 speed. Without AC, best I got was 51.3 but all highway. AC knocks it down to about 45. This last tank was an 80/20 mix of highway/town driving. Economy without AC was 49.6mpg. I'm currently running the white bottle additive and will report back on the economy at my next fill up.

By the way, the naphtha is a great solvent but the cetane boost comes from the ethylhexl nitrate. The naphthalene and 1,2,4 trimethylbenzene are both ingredients in a common high flash naphtha.

[MeteorGray]

I use a combination of Power Service and two-cycle oil from WalMart in my 7.3 Ford diesel. I do this to try to get a little more lube into the "dry" ULSD fuel nowadays and to keep the fuel system clean. Diesel fuel in the US does not protect the engines as well as fuel in Europe because the allowable "wear index" in the US is higher for whatever reason. The extra lube is designed to compensate for this sad fact.

I get pretty good economy on the highway from the big 7.3 liter engine, achieving about 22 mpg in my 8000-pound pickup when not towing, and 14 mpg when towing a travel trailer at the truck's GVWR.

[ToddT58]

I've touched 22mpg a few times over the 345,000 miles with my 7.3 with 3.73 rear end. What does your truck do withOUT the cetane boost? What other mods did you do to get the 22mpg? That's pretty good.

[Night_Sailor]

Sorry, I've been away a while.

I can report a best ever of 19mpg. 55 mph, very smooth freshly paved flat parkway driving with a minor about of city driving. 70 deg temps. I retracted my mirrors to reduce drag--they extend out for trailering and I normally keep the out. I don't expect to ever exceed this amount. Typically I see 17.5 to 18 mpg, which I'm totally thrilled with for a heavy Silverdo Dually.

Since then I've run out of the additive and saw my mileage go back down to the typical levels.

I've also carried a 4000 lb camper with it, and typically see 12-14 mpg with that. Speeds between 60 and 70, mostly on the lower end. 12.5 mpg average. I only saw 14 once in Florida, and I was using two cycle oil instead of Optilube. I use cruise control a lot unless forced off it by traffic. I'll be driving 1000 miles soon. I want to try driving a bit slower although that is hard to do in traffic and impossible at night with speeding truckers. I'll report back more later.

[Night_Sailor]

Originally Posted by euromodder

Did you change anything else at (approximately) the same time ?

A 6-11 % improvement at the low MPGs that you're seeing, is a massive change in fuel consumption.

No

[Night_Sailor]

Originally Posted by elhigh

It's nice to see this not in the Unicorn Corral. 11% is a more realistic claim than some of what gets touted there.

Start a garage entry for your ride. It's possible some of the (more talented than mine) eyes looking over your results will spot a detail that can steer you to more positive results.

Finally, go look at Diesel Dave. I don't know what the hell he's doing but he's got a truck not too dissimilar to yours and is pulling in 50mpg. I think that might be what Lone Starr would get if he poured concentrated Schwartz into the fuel tank.

I don't care if you believe me or not. I am typically skeptical too, so I'll put more data together. I'm happy for the extra range. The cost for the Optilube offsets the fuel economy gains partially. I save some money and go farther. The later is my primary goal. My larger fill ups, provide increased accuracy. I plan to try 2 cycle oil. It seems to be nearly as effective from what I've read, and much cheaper.

I bought a 1987 Mercedes 300TDT early this year. I've seen outlandish fuel economy claims on that with one guy claiming 40 mpg. He was measuring with a quarter tanks and his errors were high.

I've established a baseline on my car and have all the previous owners records, including fuel economy records. Fuel economy on that car is 19 (with lots of idling) up to 26 I think. I've been getting about 24.5 or better for highway. I live on a steep hill and need to gun it to get the turbo to spool up. Driving a bit faster I see a drop of a few mpg. I just took it off synthetic motor oil and it seems to burn less oil now. I'll try some Optilube in it. The smaller tank will reduce my accuracy some It's only about 14-15 gallons on fill ups.

[Night_Sailor]

Originally Posted by elhigh

I've seen lots of mileage claims dip a bit when drivers switch from petrodiesel to bio. Then, as often as not, they state that their mileage "comes back." I think that could be attributed, first, to the lower energy density of biodiesel as a couple of other commentators have noted, but the much higher lubricity of bio frees up some wasted horsepower by slowly dissolving deposits in the engine and keeping all the bits moving more freely.

I don't have a diesel - I wish - but I have read a few pages where the shadetree mechanic would clean parts by soaking them in diesel, and soak the really TOUGH parts, or the seized engine, in biodiesel. Just drop it in and leave it. Come back in October, it'll be loose.

Interesting.

I tried to find biodiesel a few times. Each time it cost more than mineral based diesel. I would like to make my own. Perhaps I will try at some point. For now biodiesel is out unless I can find a cheaper source.

[Night_Sailor]

Originally Posted by slowmover

Lubrizol <snip>

The old AVION truck campers were the high water mark of lightweight, aircraft construction aerodynamic housing. Is thiis the type in mind? If so, there are excellent overlapping threads on both WOODALLS and AIRFORUMS of rebuilds by a handful of enthusiasts.

.

The aluminum pickup camper I have is a Barth. But that project is on the back burner. I stripped it down to rebuild it, and then stopped. I found a great deal on a Bigfoot truck camper. I'm looking in to some aero mods for that, but that's a low priority right now. I'll try to reduce wind drag by driving slower with it for now.

[Night_Sailor]

Originally Posted by jray3

The OptiLube XPD that Night Sailor endorsed is about 90% naptha and trimethylbenzene. On Amazon, paint-thinning Naptha is $11/quart ($44/gallon) and Opti-Lube XPD is $14/quart, so just a 27% premium for the 10% of trace ingredients. (Plus pricey shipping) Trimethylbenzene is nasty stuff that's hard to buy, so it sounds worth a try from a local retailer rather than just pouring in a can o solvent, and even a 5% increase in fuel economy would be worthwhile for something that adds 11 cents per gallon (2.75%) to $4 diesel.
http://opti-lube.com/downloads/MSDS/...I_XPD_MSDS.pdf

A 5% fuel economy improvement on $4 diesel would breakeven at $25.60 per quart of additive, if used to treat 128 gallons, as claimed. Pennies, but worthwhile especially if the other benefits of fuel system cleaning and lubricity are realized...

Naptha would not add any lubricity.

This additive does improve lubricity. I noticed almost immediately that the engine ran quieter. It was like a sprinter taking off a heavy back pack.

I did run a few tanks with 2 cycle oil when I ran out of Optilube. It seems to work fine. My best tank with the camper on was on 2 cycle additive--this was in the flats of Florida--which I'm sure helped a lot.

[crashnzuk]

A boost gauge is helpful in a turbo diesel vehicle when trying to find economy. Keep your boost as low as possible for the speed you travel and it will reward you with better economy. You may even notice a mph point where boost ramps up dramatically, if this is the case you can slow your cruise speed to where it drops back down and find economy there. You will most likely find a majic speed where this happens so you can adjust your cruise speed accordingly. It takes fuel to spool a turbo and make boost, keep the boost low for economy.
Travis..