Edmunds Answers

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  • avatar zaken1 03/09/12 6:30 pm PST

    There are several reasons why exotic lubricants do not get more public attention or acceptance. One of the strongest ones is that the public usually regards cars and trucks as throw-away items; and thus sees little or no value in extending or prolonging their life. So there would be little profit potential in advertising such producuts. On the other hand; high performance motorcycles often produce enough stress on lubricants that the conventional stuff just doesn't hold up. And in those cases; synthetic lubricants are advertised for that market and are selling well. Simlarly, racers typically use synthetics.

    Synthetic tranny fluids will produce little noticeable change in fuel economy in a truck; and Chrysler is very strict about automatic tranny lubricants meeting their specific standards; so not all synthetic tranny fluid will be approved for this application. But if you can find one that is Chrysler approved for this model, I would go for it mainly because of the extended life.

    Synthetic engine oil probably carries a greater potential for fuel economy improvement than does synthetic tranny lubricant; mainly because the benefits are not only in friction reduction; but also in improving the sealing of the piston rings, and that has significant effects on performance. But here, we must distinguish between gasoline and diesel engines; and also distinguish between manual and automatic transmissions. The lubricant viscisities and formulations which work best in a gas engine will not be the same as the ones which work best in a diesel. Transmission lubricants also are similarly specialized.

    If you are interested in this sort of stuff; do not overlook the lubrication of the differential. There now are some excellent synthetic gear oils; which greatly outperform their petroleum equivalents. Synthetic gear oils are relatively new and uncommon; and have had the greatest testing and development in heavy duty trucks and in racing motorcycles; so I use those sources for these particular products. They sure do a lot to quiet down differentials and trasaxles.

    And there are important technical differences between grades of gear oil; which must be considered before selecting one. Gear oil designed primarily for manual transmissions will not contain the needed additives for use in transaxles (combined transmission and differential units; such as are commonly found in front wheel drive cars) or differentials. Transaxles and differentials have hypoid gears in them; which need specific lubricants. Gear oil is classified by GL ratings. GL1 to GL3 has few additives. GL5 has hypoid specific additives required for manual transaxles.

    For more information on synthetic lubricants; check out http://www.spectro-oils.com/

    The transaxle in my 1990 Geo Metro has always been very sensitive to the lubricant used. The manufacturer called for GL5 SAE 80. I used Red Line GL5 75W-90 in it for years; but I had the front CV axles replaced some time ago, and did not know that the shop drained the transaxle and put some generic crap in it. Shortly thereafter; the transmission began howling in third gear; and I began contemplating having to replace the transmission. Then it dawned on me that the shop that changed the axles probably drained the synthetic gear oil. Red Line is a good lubricant; but I did not feel it was good enough to bring a transaxle back from the grave. I knew from experience that Spectro makes the best gear oils that are available; and then found out that they came out with a new gear oil which is specifically designed to quiet down the new Harley Davidson 6 speed transmission (which is notoriously noisy). So I decided to go for the best, and bought 3 quarts of this product; which is called Spectro Heavy Duty Platinum 6 speed transmission oil GL5 75W-140 http://www.spectro-oils.com/?p=273 This product costs about $22 per quart!!!!! but it turned out to save my transaxle; so I considered it a great bargain.

Answers

  • zaken1 03/09/12 6:30 pm PST

    There are several reasons why exotic lubricants do not get more public attention or acceptance. One of the strongest ones is that the public usually regards cars and trucks as throw-away items; and thus sees little or no value in extending or prolonging their life. So there would be little profit potential in advertising such producuts. On the other hand; high performance motorcycles often produce enough stress on lubricants that the conventional stuff just doesn't hold up. And in those cases; synthetic lubricants are advertised for that market and are selling well. Simlarly, racers typically use synthetics.

    Synthetic tranny fluids will produce little noticeable change in fuel economy in a truck; and Chrysler is very strict about automatic tranny lubricants meeting their specific standards; so not all synthetic tranny fluid will be approved for this application. But if you can find one that is Chrysler approved for this model, I would go for it mainly because of the extended life.

    Synthetic engine oil probably carries a greater potential for fuel economy improvement than does synthetic tranny lubricant; mainly because the benefits are not only in friction reduction; but also in improving the sealing of the piston rings, and that has significant effects on performance. But here, we must distinguish between gasoline and diesel engines; and also distinguish between manual and automatic transmissions. The lubricant viscisities and formulations which work best in a gas engine will not be the same as the ones which work best in a diesel. Transmission lubricants also are similarly specialized.

    If you are interested in this sort of stuff; do not overlook the lubrication of the differential. There now are some excellent synthetic gear oils; which greatly outperform their petroleum equivalents. Synthetic gear oils are relatively new and uncommon; and have had the greatest testing and development in heavy duty trucks and in racing motorcycles; so I use those sources for these particular products. They sure do a lot to quiet down differentials and trasaxles.

    And there are important technical differences between grades of gear oil; which must be considered before selecting one. Gear oil designed primarily for manual transmissions will not contain the needed additives for use in transaxles (combined transmission and differential units; such as are commonly found in front wheel drive cars) or differentials. Transaxles and differentials have hypoid gears in them; which need specific lubricants. Gear oil is classified by GL ratings. GL1 to GL3 has few additives. GL5 has hypoid specific additives required for manual transaxles.

    For more information on synthetic lubricants; check out http://www.spectro-oils.com/

    The transaxle in my 1990 Geo Metro has always been very sensitive to the lubricant used. The manufacturer called for GL5 SAE 80. I used Red Line GL5 75W-90 in it for years; but I had the front CV axles replaced some time ago, and did not know that the shop drained the transaxle and put some generic crap in it. Shortly thereafter; the transmission began howling in third gear; and I began contemplating having to replace the transmission. Then it dawned on me that the shop that changed the axles probably drained the synthetic gear oil. Red Line is a good lubricant; but I did not feel it was good enough to bring a transaxle back from the grave. I knew from experience that Spectro makes the best gear oils that are available; and then found out that they came out with a new gear oil which is specifically designed to quiet down the new Harley Davidson 6 speed transmission (which is notoriously noisy). So I decided to go for the best, and bought 3 quarts of this product; which is called Spectro Heavy Duty Platinum 6 speed transmission oil GL5 75W-140 http://www.spectro-oils.com/?p=273 This product costs about $22 per quart!!!!! but it turned out to save my transaxle; so I considered it a great bargain.

  • texases 03/09/12 9:43 pm PST

    I'd be amazed if the total change would be 1 mpg. No 'greatly improved milage' results from sythetic vs. fresh conventional oil. Of course, those selling the very expensive sythetics will claim otherwise. They're wrong. If you want to try synthetics, go to Walmart and buy the appropriate Mobil1. And like Zaken1 said, don't mess with the transmission fluid, just replacce with the correct fluid every 30k or so.

  • morin2 03/10/12 10:59 am PST

    If your primary interest is improving fuel economy, try to find pure gas in your area. In some parts of the country, you can still find it and using this ethanol-free gasoline will certainly improve your fuel economy. It is no more expensive than the adulterated garbage E10 fuel. If you are lucky enough to have it available, be sure to use it in all your small engines too to maximize engine life - especially those expensive chain saw and boat engines. Search your state at:

    www.pure-gas.org


  • zaken1 03/10/12 2:09 pm PST

    Rick; we have to be careful of those Dodge Ram posts; many of them are diesels.

  • morin2 03/10/12 4:53 pm PST

    Right. I like those Cummins diesels. If this one is a diesel, it would be a rare one to average only 7500 miles per year. I looked for years and could not find a low-mileage example.

    I always assume "gas" unless diesel is stated. Probably not the best assumption for these in particular. Thanks for the reminder.

    BTW, off-topic, but can you get pure gas out there? I have none at service stations within 100 miles and so, have to pay $9 gallon at the Stihl shop for use in my chainsaws (still cleaning up from last 2 hurricanes). I won't run E10 in these saws.

  • zaken1 03/10/12 8:07 pm PST

    Rick, I assume it was me you were asking about the availability of pure gas; and you know that I live in northern California. The only listings I've seen for pure gas are way up in the nothern part of the state, near the Oregon border. So it is not an option for me.

    However; there are also other possibilities: (Don't laugh) but Coleman stove fuel can be used in 2 strokes in a pinch. However; it has very low octane, and would probably not run well in today's high performance chain saws. Another option used to be (and probably still is) unleaded aviation fuel. You can buy it at local airports that service small planes. It used to be available in 85 octane (not sure if that is the Research or the Motor number). But I have heard that Av gas is not as suitable for motors that run at low altitudes; because they've modified the volatile components to be more stable under the low atmospheric pressures encountered by airplanes. And some marinas that sell premixed 2 stroke outboard fuel might have pure fuel for that purpose; but I'm not certain of that.

    Your $9 per gallon Stihl fuel sounds like the price of high octane unleaded automotive/motorcycle race fuel; which is sold by some Unocal 76 stations, and is also sold by racing distributors. You might be able to find a race fuel distributor near you. (www.ercracing fuels.com) can steer you in the right direction for that one. I don't think that stuff has ethanol in it; but I'm not altogether certain. I'm just happy to no longer own any 2 strokes. Back in the 1960's; both my car and motorcycle were 2 strokes.

  • tewest 03/11/12 2:14 pm PST

    just wanted to add that it is a 3.9L V8. It runs very well and was well maintained by the previous owner. just want to keep it running good for a long time. have read that the Ram trucks were known for sludge build up in the motor. also read that synthetics cut down or eliminate sludge build up. is this true?

  • oldsmojo 03/12/12 1:07 am PST

    use the type transmission fluid the factory or owners manual recommends.trying other additives could cause more transmission problems.

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