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ContinuousWave: Whaler Performance
E-TEC vs. Tohatsu TLDI
|Author||Topic: E-TEC vs. Tohatsu TLDI|
posted 05-24-2005 12:24 PM ET (US)
I've been comparing [the Bombardier Evinrude E-TEC and the Tohatsu TLDI outboard motors] in 40-HP models. The [E-TEC] has high pressure injection at about 800-900 lbs. [PSI?] The Tohatsu is a low pressure injection at 80 lbs.[PSI?] Does anyone have any experience or knowledge about the difference? The Tohatsu is $1,000.00 cheaper.
posted 05-24-2005 01:49 PM ET (US)
The TLDI fuel system is licensed from Orbital. The Mercury OptiMax is similar and also licensed from Orbital.
Where did you find the two pressure ratings in the engines' specifications? I don't think that the pressure of the fuel injection makes a particularly good metric for a comparison. Are those numbers in pounds per square inch?
Normal atmospheric pressure is 14.7 PSI. Most engines have a compression ratio of at least 8:1, so this would imply that just the cycling of the piston up and down in the cylinder creates a pressure of
14.7 X 8 = 117.6 PSI
If the TLDI/OptiMax only has 80-PSI, it must not be able to inject fuel near the peak of the piston's upward travel, as the pressure in the cylinder would be greater than its force.
When the fuel mixture is detonated it probably creates much higher pressure in the cylinder from the explosive burning of the fuel.
I know that Mercury had published promotional material that tried to persuade readers that there was some advantage to having lower injection pressure by claiming that higher pressure would somehow damage the cylinder. This always seemed like a ridiculous proposal. Consider the cylinder is designed to withstand a constant explosion of gasoline vapor, having a burst of fuel injected at high pressure sounds like an afterthought.
I don't know the precise details of the TLDI system, but if it is similar to the OptiMax it requires a separate air compressor to be driven from the engine, usually by a belt and pulley arrangement. This robs some horsepower from the engine. The compressor pre-presurizes the fuel/air mixture and distributes it to injectors. The system also has duplicate injectors, some fuel injectors and some air injectors, so it doubles the complexity. This also doubles the electrical load, as there are twice as many injectors. The elevated pressure from the compressor has to be distributed in a high pressure rail or hose to each cylinder. There is quite a bit of plumbing and hose running around under the cowling of these engines. Fuel is also raised to pressure by an electrical fuel pump. These engines are very high consumers of electrical energy and often do not produce net charging amperes until running at fast idle. They have strict requirements for battery capacity so that they can run at low idle speeds.
In contrast the E-TEC has none of this stuff. It just has a single injector at each cylinder which is supplied fuel at quite low pressure by an electrical fuel circulation pump.
I would recommend you take the cowling off of each of these engines and observe the actual implementation of these two technologies. I think from a visual inspection you will be able to see which is a simpler, more direct approach. I often think that simpler, more direct can also be an indicator of more reliable, easier to maintain, too.
The choice to purchase a Tohatsu should also be made after consideration of their dealer network. I can't comment about Tohatsu dealers because I have never seen one. You may be able to get some help from Mercury. Mercury buys many engines from Tohatsu and imports them from Japan, selling them as Mercury branded engines. But a stand-alone Tohatsu dealer is going to be quite a rare bird to sight.
The E-TEC engine is much more than a difference in fuel injection pressure from a TLDI or an OptiMax. You probably should acquaint yourself more with it. There are over 400 articles on the CONTINUOUSWAVE website which mention E-TEC engines. I would start with this one:
posted 05-24-2005 01:58 PM ET (US)
Thanks for the info. I will research farther.
posted 05-24-2005 02:05 PM ET (US)
Also, I should mention that the E-TEC engine is manufactured in Wisconsin by Bombardier. They employ several thousand nice folks at their modern plant. If you buy an E-TEC, the money you paid for it flows around until it comes out in Wisconsin, where it then flows into the U.S. economy. Some of it might come out in Canada, but not all that much of it.
The Tohastsu is manufactured in the Far East. I am sure they employ some nice folks over there making the Tohatsu. If you buy the Tohatsu most of your money flows overseas and comes out in the Japanese economy.
Every time someone buys a foreign product in preference to a domestic product, we send our dollars overseas. This goes on at the rate of billions of dollars a month. In order for us to not run out of dollars, the nice folks overseas keep sending them back in the form of capital investment. If this did not happen at an equal rate, the value of our dollar would fall. So far, we have managed to keep up appearances here in the U.S. so that folks like to send their dollars back to invest in our capital markets at about the same rate we like to send them money for their outboard motors and other products.
We use the capital to make films like Star Wars, and then we export them and get some of the money back.
The bottom line: if you want to keep buying manufactured goods that are made in foreign countries in preference to buying manufactured goods made in your country, you better start thinking up ideas for a movie script, because in a few years we are gonna need another good idea for a movie to get some of our dollars back from overseas.
posted 05-24-2005 02:08 PM ET (US)
I've been hearing that "sucking sound" loud and clear for the last few years.
posted 05-24-2005 04:02 PM ET (US)
There is a brief description of the difference between LPDI and HPDI on the Tohatsu website. http://www.tohatsu.com/tech_info/index.html . In the TLDI FAQ section. I would like to see something a bit more scientific though.
posted 05-24-2005 06:22 PM ET (US)
Also, not_every_Tohatsu dealer is authorized to sell or perform repairs on the TLDI motors. The TLDI franchise is seperate from the normal Tohatsu authorized dealer.
posted 05-24-2005 07:44 PM ET (US)
As long as Optimax has been mentioned, Mercury is claiming, in the 2005 catalog, that the 90 Optimax both out-acclerates and gets better fuel mileage than the 90 E-Tec. All this from an engine with a 50 lb weight disadvantage. Whether this is Madison Avenue, or true, I have no idea. Both are 3-star engines. From Whaler's 170 data, this would interpolate to mean the Mercury/Yamaha 90 4-strokes will also outperfrom the E-Tec 90.
So the low pressure, air atomized fuel injection system must be pretty good. Evinrude and Yamaha do not use air to assist in the injection process.
Regarding the Tohatsu/Nissan branded engines, everybody seems to think they're slugs in the above 30+ HP versions, for some reason, but highly reliable, and more oriented toward the commercial market.
Liter for liter displacement, the Optimax's outperform both the Ficht/E-tecs and HPDI's, and are known for the best fuel economy besides. The 135-175's are only 2.5 liters, and the 200-250's are only 3.0 liters. The others had to go to more cubes to keep up, varying from 2.6 to 3.3 liters.
Currently the big block Yamaha 250 and 300 HP HPDI's are experiencing serious problems, but I don't know why, or how it's being fixed. But it's killing their reputation for good high HP engines, dumping the business right over to the Verados. I am wondering what the HP limit might be for DFI technonogy to perform reliably? So far the 250 Optimax and E-tec seem to be the leaders in this category. Above 250 HP, you really only have one choice, the Verado
posted 05-24-2005 08:21 PM ET (US)
I have to agree, despite the greater complexity, the OptiMax engines are good performers. In some aspects they are the two-stroke low-emission leader as far as price, performance, and fuel economy. What is really weird is the apparent line of demarcation (and I mean this figure of speech in the same sense as Pope Alexander VI meant it when he drew the line in 1493 to divide the spheres of influence in the New World between Spain and Portugal) whereby Mercury uses the technology in the higher horsepower engines and Tohatsu uses it in the lower horsepower engines. It is almost as if this were part of an agreement between them. Who knows?
The result is that in a 40-HP outboard, the only low-emission engine you can buy that is made in the U.S.A. is the E-TEC. Anything else just sends your dollars abroad, off to some eventual recirculation on the island of Honshu in the nation of Japan.
If you have any questions about the TLDI, just pick up the telephone and give Mr. Toshihiro Nakajima a ring at (+81) 03-3966-2951. He can tell you all about it. Watch what time you call him, as he's in Japan, and they're keeping local time at GMT +9. Adjust your watch accordingly.
posted 05-24-2005 08:30 PM ET (US)
It's quite possible that Orbital licensed Merc on the high end of the HP spectrum and Tohatsu on the low end, or above a certain displacement and below a certain displacement. The displacement dividing line might explain why Merc has a 375 lb 75 HP 2-stroke DI motor, which must one of the hardest motors in the world to sell. Evinrude got rid of their heavy 75 DI 2-stroke product a couple of years ago now in favor of the E-TEC.
posted 05-24-2005 08:33 PM ET (US)
Oh, I forgot to address the $1,000 price difference. This is probably due to the fact that Tohatsu is dumping (or selling below fair market value) their excess production capacity from their Japanese plants into the U.S. market. A year-long investigation by the United State International Trade Commission confirmed that the U.S. market for outboard motors was being used by Japanese manufacturers as a dumping ground for their excess production capacity. It turns out, in the legal definition, that dumping like this is not illegal if it does not harm the domestic producers. The folks at the USITC seem to have decided that the "domestic producers"--which means Mercury and Bombardier and the 10,000 or so folks they employ in Wisconsin--were not being harmed by this action by the Japanese manufacturers. Therefore, it was not against the trade laws of the United States for the Japanese to continue to undersell their products on the domestic market.
So you can thank the three commissioners at the USITC who voted in favor of the Japanese and beat out the two commissioners who dissented, and you can help yourself to a $1,000 discount on that Tohatsu engine. The funny thing is the dumping margin was computed to be around 22-percent, so if we take
$1,000 / 0.22 = $4.455
I bet we will discover the price of a 40-HP outboard.
Let me know if my math is in the ball park.
posted 05-24-2005 09:57 PM ET (US)
LHG- There you go interpolateing again! You give your opinion to support the Merc Company line but the hard facts don't always support it. I'm sure your not going to put your money on chances that the Optimax will even be produced 2 yrs from now.I just read that the EPA just gave the Clean Air Award to BRP for the E-TEC(the first for an outboard manufacturer) and The Wisconsin Governor just gave First Place Product and Best in State to BRPs E-TEC. I thought of you when I saw that and how much it would tick you off!(Being Merc is a Wisconsin favorite). Even POWERBOAT REPORTS gave kudos to BRP in the June issue. The fact is the Verado is still too heavy for many boats. How in the world did you get the idea that 300hp E-TECs could not be produced? By the way the freezer is filled with salmon and soon we will be catching Kings in Door County!(All being caught with a smooth E-TEC on the back of the boat)
posted 11-08-2006 09:42 PM ET (US)
Just to follow up on this older thread, I have to point out that the situation I described above regarding the export of our dollars overseas via the purchase of imported products being balanced by those dollars returning as capital investments in our economy has changed. After the new round of regulations imposed on the American business sector via the Sarbanes-Oxley (SOX) legislation, the investment of foreign capital in U.S. capital markets has declined. There is just too much regulation and documentation required by SOX for some foreign investors, and they have taken their billions of dollars elsewhere to invest. Those crusading legislators that stampeded SOX regulations perhaps never thought of the effects it would have. Once economist described it as something like ordering from the menu at an expensive restaurant but never looking at the prices.
Yes, now we have some of the most complex and demanding corporate accounting laws, but we have driven off a lot of investment and flow of capital from our country with them.
You may want to keep that in mind when you are shopping for goods which have been imported for sale by non-US companies. If you buy an outboard motor that was not manufactured in the United States, you will be sending most of your money overseas to flow into a foreign economy. And the chances of those dollars returning are becoming increasingly smaller.
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