My librarian was unable to find any good articles involving mixing diesel and gasoline in any automotive use. Gasoline and naphtha, gasoline and hydrogen peroxide, gasoline and acetone, but not gasoline and diesel.
The engine (Olds 350 Diesel) was specifically designed as a diesel; it was not a “upgraded” gasoline engine. The block was thicker as well as the crank diameter. The main design flaw was the failure to include a fuel/water separator & drain. In addition, some craptacular diesel fuel hit the market about the time the engine came out. Once the water/gunk stuff got into the injection pump, you were screwed with, at a minimum, a blown head gaskets, at worse, a broken crankshaft, etc. They also cheaped out on the number of cylinder bolts. They wanted to make the engine on the same line as the gasoline ones so they made up for this by stretch bolts which can only be used once; service personnel kept reusing them (resulting in more blown head gaskets and worse). Of course, there were other problems with the design (the injection pump was chain driven and that stretched over time, screwing up the timing of the fuel delivery), but the blocks themselves were durable enough to be used in drag racing (admittedly though they were gasoline powered). GM did a poor job of anticipating how the consumer would treat the engine along with failing to educate the service people on the repairs. Had GM fixed these problems early on, IMHO the engine would have been a modest success. But GM wasn’t that kind of company–come to think of it–it isn’t one at all.
The Central Scrutinizer, I see my first post was ignored, but I have another question: What is you height and weight?
I want to know how serious you are about saving fuel.
Good point, he would probably get more of an increase in gas mileage by taking a giant dump before driving then he would by leaving the windshield wipers off.
Well, diesel fuel probably DOES make a good laxative so maybe he is onto something here. Of course he will probably want someone ELSE to drink it first to test it out and he won’t be telling them what he spiked their drink with cause what they don’t know can’t hurt em.
Billfish, Well, go to one of those day labor places and rent someone for the day and have them drink it. If it does not work, just return him to the day labor place. If it does, then you try it next, see?
Seriously I am glad to see people trying things but I would also think diesel would have less power and it would make smoke, so I doubt this is the answer.
Maybe the rental car agent. Two birds with one stone and all that.
It wasn’t so much to do w/ the EPA rating as it has been w/ the noticeable drop in fuel mileage we’ve had once gasohol (E10) was mandated in this area. Yes, people were indeed complaining of the less-than-expected mileage, but that was probably due in part to their continuing to drive as if they were driving a high(er) performance vehicle, w/ a larger engine, not designed specifically for high mileage.
Another point to consider when they experienced lower results might have been that many of them turned to the Prius after their history w/ getting stung @ the fuel station driving a relative gas-guzzler (particularly as gasohol fuel costs in our area kissed $4/gal during the summer of 2007), while then never bothering to change their driving habits. Anything will use more fuel when driven incorrectly/aggressively & I’ve seen a lot of Prius owners trying to drive them like sports cars! I can, & have, driven quite briskly w/ a Prius & it still gets impressive mileage, but as I originally said, our mileage was originally consistently ABOVE what the EPA estimates were, regardless of others’ returns.
What my original posting regarded was the noticeable & consistent reduction in fuel mileage, after the introduction of gasohol into our area & despite doing some learning how to change our driving habits to suit the personality of the vehicle to make the best of the technology (like driving below 40 mph so that it runs on electric).
& my original Question was whether the addition of diesel to the mix might improve/return the original efficiency lost due to the lower energy content of the gasohol, & what might the optimal % might be while avoiding driveability problems. This regarded all gasohol-fueled vehicles, not just the Prius.
Thank you for giving some thought to your response.
Perhaps I should have qualified my response w/ the words “historically”. As I said, I’ve been in that field a long time, & today’s marine engines have advanced & increased in their complexity in relation to their ancestors, along w/ their automotive counterparts but typically the technology has lagged behind the automotive by (it seems to me, having my face & hands in them regularly & having sold them often) roughly 10 years.
I suspect that’s been a function of several factors, not the least of which has been that the technology is proven, is not so cutting-edge (expensive), that marine engines are run much harder than automotive, that they run in a much more challenging environment (parts, especially electrical in any form & water, particularly salt, just don’t get along) & boats (esp. gas fueled!) have a higher incidence of blowing up, being in a closed engine room (for inboards/stern-drives) w/ no convenient service station with which to just pull in. Not to mention the “run hard & put away wet” habit of a lot of recreational boaters…
Yes, since my specialty has been outboard motors, I know quite well just how complex they’ve become, w/ digital fuel injection along w/ supercharging in some models adding to the initial cost, service cost, performance & improved efficiency w/ reduced emissions resulting. Gone are the days of carbs & points, but you couldn’t argue that those old-fashioned methods were a lot more rugged; just ask someone who’s sunk a motor just how expensive replacing all those fancy fuel injection & electronic systems can get! Hard to screw-up carbs & points… I know, I’ve done quite a number of raisings & insurance work.
Now, as to the comment about marine engines being basically automotive w/ just a few parts (accessories) being changed, that wasn’t always the case, although I’ve encountered many occasions where someone tried to save themselves a few bucks & treated them like auto engines. Some were lucky & just had to have a service call to have the correct parts replaced. Some died.
There was a day when you’d most likely find 4-bolt mains, sleeved cylinders, really heavy-duty designs being used. Yes, you might be able to marinize an auto engine with just a few “accessories” but things like ignition-proof electrical systems, high-flow cooling systems, brass & stainless parts, marine-grade head gaskets, spark plugs, oil, lubes, greases & the like are a necessity if you’re expecting them to last more than a few years (not to mention maybe making it back alive!) The ignition & fuel systems in marine engines, esp. outboards, are more often than not specifically designed for the increased demands of the marine environment. There are a lot of differences. You’re correct, no engine likes water anywhere but where it belongs; it’s just part of the job for a marine engine to be able to take the abuse that an auto engine will never encounter.
That’s why they tend to be tougher & simpler. When I was based in Annapolis & a little younger, I used to be THE referral for outboard service from the marine version of Triple-A. I also used to be the informative source for a Q&A marine engine column in the local paper. Now I do more work in a wider area such as surveying on both sides of the Chesapeake & along the Atlantic coast as well. I’m spread a little thinner these days…
But perhaps this deserves another topic heading?
Yes, I know, I looked too… but I did have fun w/ an old Pontiac w/ a 455 HD engine & a 4.33 rear, modified (carb, ignition system, exhaust, heads, transmission, cooling system) in a few areas, & using H2O2 (peroxide) in what was supposed to be a water-injection system… still couldn’t pass a gas station, but I did double the gas mileage (from~6 mpg to ~14 mpg) while still being able to pass just about everything else. & I only had to change the plugs every year or 2 instead of 3X annually. But that was back in the day of leaded premium exceeding 100 octane being commonly available, no alcohol… sure do miss that exhaust rumble!
But, thanks for looking! Can I go & blow something up now? 
Well, this being an auto engine (never laid hands on one in the marine field) most of what I’d heard was that they’d never designed it to deal w/ the 2-3X increase in compression ratio. Also for the same reason, Olds seems to have made the best auto engines, but I’d only seen 1 in a boat, & that being gas-fueled. I’ve encountered stretch-bolts & been aware of the prohibition against re-using them. I’m sure that the Olds engines were GR8 racers. They certainly were tough. I do know that GM DNR them for towing… there’s a lot more to diesel engines than just thicker castings & cranks, etc. I suspect that the fuel you mentioned might have been the increasingly low-sulfur variety. Sulfur, while being a culprit in acid rain along w/ NOx, protects critical parts in the extremely high pressures & tolerances of the diesel injection systems. Today, like adding valve-seat wear inhibitors to older gas engine fuel, adding something to help compensate for the reduced lubricating properties of modern ULSD fuel in diesels is a smart practice. Injection pumps & injectors aren’t cheap… & the tolerances are close enough that they have to be assembled at the same temperature.
In my 50 years, I’ve lost a few inches (I used to be 5’11") & gained a few #s (I used to be ~175 steady).
Perhaps I might be able to cut my waist-long red hair & my DD-cups off, ride my cycle w/out a helmet while naked… even if I didn’t increase my mileage, the $$$ you might pay me to see it would pay for my fuel easily… you think?
Hmm… perhaps I should complete my profile section??? 
Doesn’t pay to go making assumptions about someone… I used to bench 250 & win bets arm-wrestling jackassed bigots… all w/out being a prick, or owning one! :eek:
Actually, castor oil makes a better laxative, so I don’t have any Questions there; some else has already tried it.
PS - Not a prick 'cuz I don’t have one!
Hey, the FDA & the Army try that all the time, so you might just be onto something there…
I don’t know about the power issue (yet!) but an earlier response reported no smoke or running problems & that was ~20%.
Yeah, now you’ve got it! Only I’d just have to get them into a headlock while I poured it down their throat… it’d be tough not to spill any while they were strugglin’…
You don’t need one to be one. Experimenting with equipment you don’t own is pretty close to the textbook definition of a prick.
I know, but it sure does help!
Hmm… I’ll remember that when I rent a chainsaw to find out how quickly the teeth get dull while cutting those things off… :eek:
You are talking out your a$$. You’ve completely failed to address your claim that marine engines are simpler. You’ve done nothing to substantiate the claim. Since this thread has evolved, you’ve wanted to qualify yourself and you’ve not done it.
The most prolific marine engines (Volvos, Mercruisers, Honda and Yamaha) are similar to their auto counterparts, and given some special attention to be adapted for marine use. The big diesels have a similar story to tell.
Using RainX to save wiper usage (and gain MPG) is easier than dropping some pounds that have a real-world and substantial impact on mileage. How convenient.
Unless you are fit/lean, you are wasting gas. FURTHER, the am’t of fuel required to deliver and transport all the (extra) food you eat isn’t very ‘‘green’’.