Biodiesel as gasoline additive

[trollbait]

I'm about an hour north of Philadelphia and work right outside it. The commute is a little over 30 miles one way. Except for the little bit of surface streets at the beginning and end, I'm on a 4 lane highway, route 309. It's roughly split into thirds along my trip.

The first going in to work is expressway with rolling hills. My home is at a higher elevation than work. By the one GPS it might be has much as 500ft, but this GPS once said I was below sea level at the beach. What ever it is, most of the change occurs along this stretch with 2 big, steep hills. I do EOC down these hills in general practice. With the colder mornings and headlights on at night, I decided to be kind to the new battery and haven't been during the test. I do neutral coast them, and pulse and coast between 50 and 60 mph on the express way sections.

The second section is a business district, with lights and heavier traffic. Speed drops to 35 to 45 here. I coast when I can, and try to time lights. I might FAS at the railroad crossing and one long light, but It's not as long as during summer as battery voltage drops quicker.

The final section is expressway again. Still rolling hills, but without any major individual slopes.

Recently, temperatures were around 50F in the morning and around 60 on the trip home. It's going to be dropping. I had wanted to start this experiment sooner, but had some problems with my first batch of biodiesel. After the current tank, I think I'll try the insulation and WAI with the biodiesel. Then I'll do some tanks without the biodiesel.

[trollbait]

Finished with 30.1mpg yesterday. Had plenty of rain and temperatures dropped. Got 32.4mpg in 35F temps this morning. It looks like the near 60s weather is gone for the year. I might actually be shoveling snow this Sat.

[trollbait]

The latest tank came in at 30.22mpg.

For most of the past week the temperatures were at or near freezing for my morning commute. It would have been another week before I saw such temps in previous years. Despite being uphill, my commute home in milder temps returns a higher trip economy now.

I removed the tube between airbox and fender wall, and put some insulation in the engine bay. I'll get the tube shield in that intakes above the exhaust, behind the engine, in place this weekend. In absolute terms, this WAI setup doesn't help improve fuel economy for me, but it does speed up warm up and holds some warmth while parked. If I hadn't been trying to keep the tank conditions consistent, I'd have put it in place last weekend.

[trollbait]

Final tank with biodiesel came to 32.32mpg.
That's an average of 31.21mpg for those three tanks.

Slightly better than the previous tank average, but in the middle when compared to previous years.

The report claimed near or better fuel economy with alcohol free gas. So I think it's safe to say I had no improvement with my mix; 1:1 biodiesel to paint thinner with a final concentration of biodiesel of 0.2% to 0.3% in the tank. That is if my mileage doesn't plummet in the next couple of tanks.

I think I might try going up to a 0.5% final concentration. I don't think going would be a problem, it's just any more and it starts getting impractical for me to make enough biodiesel in these tiny batches. Another consideration is that with more added, energy content of the biodiesel might be factor. If so, for most of us, it would be more practical to try experimenting with ultra low sulfur diesel.

Of course, the isopentane might be the key. I'm going to look into other ready available solvents to use in place of the paint thinner while doing 2 to 3 biodiesel free(I'll keep adding the paint thinner) tanks. Any suggestions?

[theholycow]

If I remember correctly, toluene and xylene (available at home depot in gallon cans) are what refiners use to adjust octane rating and are used for DIY octane boosting; regardless of octane, they would therefore be safe solvents to use. Also, people have posted on this site about using acetone.

For your biodiesel, why not buy some instead of making it or buying ULSD?

[trollbait]

I checked for nearby sources of biodiesel before starting off. The only available stuff was blends which may or may not be heating oil. If it seems to be the btu content is the factor, I'm willing to try ULSD. Heating oil had a magnitude more sulfur than the old road diesel. I don't think it would be good for the cat.

It may be an issue of too much biodiesel though. There was still over a quarter of tank left when filled up with just gas and a little paint thinner. The little driving I have done so far is staying above 32 mpg.

[trollbait]

First tank without adding biodiesel came to 31.85mpg.
There was some leftover biodiesel, but more importantly, the weather has been pleasant here for the last week. Highs around 60 with my morning commute at the mid 40's to 50.

[trollbait]

It's been awhile. I had an issue that may of had an affect on the previous testing. Still had some biodiesel left, so I'm taking another try at it.

Since a bottle of injection cleaner is usually 12oz., I'm sticking with 10oz. total of additive. It will be 5oz(150mL) of the biodiesel and the rest the solvent.

The three previous tanks were 30.98, 30.86, and 31.47 mpg with an average of 31.1mpg. In first tank with additive, the biodiesel was mixed with the paint thinner, and the mpg was 30.37.

I'm now using acetone instead of the the paint thinner. Of the readily available solvents, it has the lowest density and boiling point, and thus closest to isopentane. The tank with the acetone/biodiesel mix returned 31.56mpg.

[trollbait]

The three tanks with a biodiesel mix were 30.37, 31.56, and 33.27. The first tank without is 32.93. Still might be some residue biodiesel there. So we'll have to wait for the next to call it, but with the effort of making the biodiesel, it is looking like how I'm doing it isn't worth the work.

The mild winter, with some spring like days, didn't help in controlling the temperature variable. So it might be worth revisiting. Without knowing the specifics of the mix in the paper though, it will still be a lot of guess work.

Based on some rough calculations, it'll take 1 to 2 quarts of biodiesel or diesel in 10 gallons of e10 to raise the btu content to straight gas. At that concentration, diesels might effect viscosity. They will lower the octane.

[Jay2TheRescue]

At those concentrations I would be concerned with the possibility of oil fouling the plugs, O2 sensor, and the Cat converter over the long term.