6K miles - oil consumption stopped.

6K to 10K miles - kept using Mobil Drive Clean. No oil consumption for normal street driving.

10K to 20K - switched to Mobil 1 and oil consumption came back.

20K to 34K - changed back to Mobil Drive Clean and oil consumption stopped again.

To 34,500 miles (current) - Amsoil, and lost one "X" of oil, about 200 cc, in 500 miles of regular street driving.
===

My car eats syn oil, but not dyno oil. Is there an explanation for this?

Thanks.

 

Interesting. I just finished my 1st 1,000 miles on Syn oil, including one track day, and it hasn't burnt a drop. The motor now has 17K on it (switched to Syn at 16K) and it stopped burning oil somewhere between 8 and 10K miles.

The explanation might just be slightly looser tolerances in your motor and the thinner film of Syn oil might sneak by the rings in your motor. Maybe.

 

Spider,
Which Amsoil are you running?

 

Regular 10W30, not the XL.

 

are you checking it in the same situations i.e always hot or always cold? checking it on a level surface etc etc? Also, one X isnt that big of a deal, see how long it takes until you need to add half a quart, it might be a while longer...

 

synthetic oil is thinner and is more prone to getting burned off quicker than conventional. that is why im sticking with castrol gtx10w30.


btw you're not the only one. i know lots of owners who realised there motors started to burn oil again with mobil 1.

 

I do burn oil with Synthetic...Royal Purple...about 1 x per 1000 miles. I don't burn any at all with dino oil (at least not enought to be noticeable between oil changes).

 

road rage will put to rest a lot of misconceptions about syn oils, lets see if he can chime in.

for the record, switched to syn at 3750 miles, been running it since, now have 30k miles. Oil burning stopped at 10k.

 

Every engine is different. I know some people claim that their cars don't burn any oil from the start...

 

I am not questioning the veracity of anyone in this thread - your anecdotes are your anecdotes. However, it is hardly scientific, and the conditions and variables so great that any attempt to draw a conclusion from those anecdotes just doesn't cut it.

There is no reason that a mechanically sound engine will "burn" or "eat" synoil at a rate faster than mineral oil. In fact, the opposite is more likely true, since the film strength of synoil is higher, it makes a better seal at the ring/cylinder interface, reducing blowby. If a car has developed some ring wear or has striations at the ring/cylinder interface, it will chew up oil, and synoil's ability to flow readily into minute spots could conceivably raise oil consumption a bit, but not night and day as has been stated here.

For those of you who are experiencing oil consumption, are you using aftermarket air filters (I am doing a mental survey)?

Second, the volatility of even the best mineral oil is usually 50-100% higher than a synoil, so oil losses due to the lighter oil factions (smaller molecules) in mineral oil will be greater, especially in hot weather and when the car is driven hard.

Synthetic oil is not thinner, unless the manufacturer has indexed its viscosity on the low side of the range for the weight it is spec'd at - Mobil 1 tends to be on the low side, Red Line on the high side. Synoil is more lubricious, and more slippery, so it seems thinner.

There are, and always have been, a lot of myths about synoils, and one that stuck around a long time was that synoils somehow slipped through the engine - well, given the lousy mechanicals of 1980's US cars, that may have been true, but in a Honda engine, with its precision design and manufacturing, it isn't.

Older cars often had bad seal designs (like GM's on the small block until they finally went to a one-piece design in 1986), and then the lubricity of synoils would cause them to leak at a faster clip than equivalent mineral oils, but again, that was then, this is now. Ester oils actually swell seals, and need a bit of PAO or a seal stabilizer added to avoid too much swelling.