Synthetic and Motor Response

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Aug 15, 2002
I just changed my oil to valvoline synpower 5w-40 at 10k and immediately noticed improved response (I have a VW 1.8 turbo engine). The engine runs like it received a tuneup or something. Had Castrol GTX 5w-30 in the engine before and it was more noisy and a little more sluggish with that oil. From reading these threads by some very knowledgeable people (thank you all), my impression is that switching to synthetic may reduce some engine noise but not necessarily improve response, correct? But a differences in viscosity may improve response (heavier oil reduces HP)? So now I'm curious as to whether the dealer put in something heavier than gtx 5w-30 in my previous oil changes, or worse yet, perhaps the new dealer didn't put in my Synpower 5w-40 but put in something light from their drum
Just my $.02. The difference in engine noise may be imagination. Viscosity is viscosity and that's what determines much of the lube qualities. Things like Zinc and Moly will protect in conditions where normal oil films break down (boundary lub). The advantage of a syn oil (as you probably know) is they tend to operate over longer periods of time without "breaking down". Also they can protect better in temperature extremes. Conventional oils can do this too but they rely on additives to help them along. I believe if you continue to read here and want to upgrade your oil you may want to switch to a 40 wt. (just my opinion). You can probably do better than the Synpower-which is not a "true Synthetic" (Mobil 1, Amsoil, Shaeffer's-etc)-especially if you want to extend your interval and do an oil analysis.

Welcome to the board-
I've noticed something similar to what you felt. I attribute the improved engine operation to faster turbocharger response with the synthetic oil.


I personally never felt any difference between Tech2000 10W30 and Delvac 1 5W40. Unfortunately, however, I sold the car before I was able to take an oil sample of Delvac 1. But, I am still sold on Delvac 1, and will be my next oil of choice on my next oil change with my new car.



Originally posted by sprintman:
My turbo was most responsive with M1 0W40 TS. Made most power on dyno to with that oil/Militec 1 combo.

Thanks for the responses. It's amazing to me that oil can have an impact on horsepower. I was skeptical at first because I had heard claims about this. but now that I have felt it in my own motor, I guess I believe.
Back when I was in college I had a '79 Diesel Rabbit. I used to change the oil every 3 to 5K with Mobil 1 and a VW filter (I forget what grade I used to use). After changing the oil I always noticed a difference. The engine ran quieter and smoother. That little motor used to shake, rattle and roll but I drove it for 200K miles and then sold it for $1000 (it was immaculate). I did my third head gasket at 185K miles and the inside of the head was SPOTLESS.

Funny but that was my favorite all time car. I've had niceer cars since but I would take that Rabbit back in a second. It was the last of the German built Rabbits. I really miss getting 50MPG
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