I recently purchased Bg Synchroshift 2 full synthetic from www.roadraceengineering.com for 48$ for 3 quarts as opposed to 3 quarts of regular BG synchroshift for 29$ Being the fourth fluid ive tried I figure I would share my experiences and opinions for new dsm'ers.
I have tried various transmission fluids in my car up to this point being an owner for 6 years and hope my experiences can help people out. The only information I will be unable to give is cold weather testing because I store my car during the winter months.
Penzoil:
The most recent was Penzoil synchromesh, which I have to say for the cheap price and autozone availability is a nice gear oil for short term. the transmission was very smooth with this fluid initially, but it seemed to wear fast. on a very hot day two months ago I ran into a problem while driving my car for about 5 hours straight where it did not want to go into first or third and fourth. It was not a clutch engagement issue, I believe the oil was just breaking down under the stress. It was about a year old with 10k miles on it. I had put this oil into my car as well when i installed the 6bolt 15k before that. I do recognize that my third gear has deteriorated in these last few years due to wear, age and power output of the car, and it has started giving a lil gear rub going into third over 7k. Some of this might even be attributed to the oil.
Mobil 1:
Before that I had Mobil 1 full synthetic gear oil, which is a nice gear oil, and I never had any problems with it besides it did nothing for the notchiness of my transmission. It was readily available at autozone so i gave it a shot to replace my aging Bg synchroshift 1. For the price I would not recommend this fluid for people who like to switch gears quickly and smoothly, although it seemed to protect and wear well.
BG synchroshift 1:
Bg synchroshift 1 I installed in my car twice and I never got a good read on it, at the time I was plagued by clutch engagement issues for two years due to faulty clutch components. I never really got a feel for the jokingly proclaimed "transmission rebuild in a can." However I have to state that for about a year I drove on a badly damaged clutch and would force the transmission basically clutchless into 1st through 5th MANY times with no immediate damage which i attribute to this fluid.
Bg synchroshift 2 Full synthetic.
I have had this fluid in my car for a little while now and have to say it is definately worth the extra money! The transmission does not feel like it has 138k(40k modded)miles on it. Every gear is smooth and notchless and the transmission feels fantastic shifting into each gear including my bitchy 3rd gear at over 7000rpm. After hours of driving the fluid does not fatigue like the penzoil and driving is certainly more enoyable. Now if this fluid keeps this up for 15-20k of mileage and protects like I know Bg synchroshift 1 does, I will be convinced that this may be the absolute best transmission fluid for our cars.
Gm Synchromesh:
I have never used this fluid, however I have read and heard that this stuff is comparable to Bg synchroshift 1 at a lower price. I hope someone will add on to this thread their experiences with it.
Conclusion:
for a short term goal, for example: if you know your going to be changing the fluid often or the transmission is on its way out or you are breaking the transmission in and will change the fluid shortly I would use penzoil synchromesh. If you plan on sticking it out with the transmission or dont expect to service it soon I would at least go with Bg synchroshift 1 and if you are the "only the best for my baby" kind of guy/gal like myself I would pay the extra and get BG synchroshift2.
I have tried various transmission fluids in my car up to this point being an owner for 6 years and hope my experiences can help people out. The only information I will be unable to give is cold weather testing because I store my car during the winter months.
Penzoil:
The most recent was Penzoil synchromesh, which I have to say for the cheap price and autozone availability is a nice gear oil for short term. the transmission was very smooth with this fluid initially, but it seemed to wear fast. on a very hot day two months ago I ran into a problem while driving my car for about 5 hours straight where it did not want to go into first or third and fourth. It was not a clutch engagement issue, I believe the oil was just breaking down under the stress. It was about a year old with 10k miles on it. I had put this oil into my car as well when i installed the 6bolt 15k before that. I do recognize that my third gear has deteriorated in these last few years due to wear, age and power output of the car, and it has started giving a lil gear rub going into third over 7k. Some of this might even be attributed to the oil.
Mobil 1:
Before that I had Mobil 1 full synthetic gear oil, which is a nice gear oil, and I never had any problems with it besides it did nothing for the notchiness of my transmission. It was readily available at autozone so i gave it a shot to replace my aging Bg synchroshift 1. For the price I would not recommend this fluid for people who like to switch gears quickly and smoothly, although it seemed to protect and wear well.
BG synchroshift 1:
Bg synchroshift 1 I installed in my car twice and I never got a good read on it, at the time I was plagued by clutch engagement issues for two years due to faulty clutch components. I never really got a feel for the jokingly proclaimed "transmission rebuild in a can." However I have to state that for about a year I drove on a badly damaged clutch and would force the transmission basically clutchless into 1st through 5th MANY times with no immediate damage which i attribute to this fluid.
Bg synchroshift 2 Full synthetic.
I have had this fluid in my car for a little while now and have to say it is definately worth the extra money! The transmission does not feel like it has 138k(40k modded)miles on it. Every gear is smooth and notchless and the transmission feels fantastic shifting into each gear including my bitchy 3rd gear at over 7000rpm. After hours of driving the fluid does not fatigue like the penzoil and driving is certainly more enoyable. Now if this fluid keeps this up for 15-20k of mileage and protects like I know Bg synchroshift 1 does, I will be convinced that this may be the absolute best transmission fluid for our cars.
Gm Synchromesh:
I have never used this fluid, however I have read and heard that this stuff is comparable to Bg synchroshift 1 at a lower price. I hope someone will add on to this thread their experiences with it.
Conclusion:
for a short term goal, for example: if you know your going to be changing the fluid often or the transmission is on its way out or you are breaking the transmission in and will change the fluid shortly I would use penzoil synchromesh. If you plan on sticking it out with the transmission or dont expect to service it soon I would at least go with Bg synchroshift 1 and if you are the "only the best for my baby" kind of guy/gal like myself I would pay the extra and get BG synchroshift2.
Stock tranny. 8,300rpm powershifts in 90-100F summer heat and the fluid is in good shape when I drain it. Works fine. 
