I don't believe sythetic oil has a gross advantge over "regular"oil, and therefore will not bother with using it. So maybe the oil's properties do not break down as quick, and it's possible to go 7-10K miles before changing oil. There is still going to be a **** load of metal particles causing abrasions to surfaces, which you wouldn't have by merely changing oil at 3-4K.

My question comes from cars and motorcycles I have seen for sale. The seller states that the vehicle has always been ran with synthetics and the new owner must continue using synthetic oil. Why? I don't think mixing hydrocarbons of automotive oil will cause an explosion or eat away at metal like an acid, so what gives with this??

T

 

I have used synthetic oil for the last 10 years and believe it helps greatly!
I use Castrol Syntec (this isn't a commercial). My ex-wife (now) ran my car and the fan quit working, rad completely dried up from the heat, engine still ran good. On another occasion she ran it on the highway and the check oil light came on. She drove it to the next service center (about 20km) and found out the oil pump had quit.

Synthetic oil doesn't break down as much from the heat, and this means it stays cleaner longer. Also, there shouldn't be any metal particles in the oil if your filter is working properly. Synthetic oil also doesn't get thick due to the cold weather like ordinary oil does, therefore lubricating your engine faster, creating less wear.

 

as for the 7-10K, change the filter at about 3-4k and itll be fine to 7-8k, or use the Fram extended life filters.

 

Go you!!! That was an amazing response. I (v) SYNTHETIC

 

I believe synthetic oil also more slippery therefore less friction.

 

It isn't even a debatable subject. Petroleum oil is obselete!