thirstys2k

My 01 AP1 (about 85,000 miles now) drinks synthetic oil like no tomorrow. It has its whole life since i've owned it (since about 40,000 miles). I've tried Amsoil ATM, German Castrol, Mobil 1 extended performance. It burns them all up at an excessive rate.

I want to try switching back to a conventional oil to see if it will slow down my consumption a little. Can anybody recommend a good 10w-30 for this? I have heard Havoline GF4 is decent, or I was maybe thinking of trying Castrol GTX 10w-30. Any suggestions?

zeroptzero

Havoline is decent as it has a good dose of moly in it, Castrol GTX is perfectly fine, as would be Penz yellow bottle.

You might want to consider a good High Mileage oil, they do a pretty good job of cleaning which is what you might need. In some situations they can work to reduce future consumption. It takes about two oil change intervals to stabilize oil consumption issues that aren't mechanically related, so I'd run a high mileage oil for two OCI's and see how it goes. You might see higher consumption on the first run, and reduced consumption on the second run, so two runs is always recommended in order to get a better idea of what is going on. Valvoline had a good HM oil in Maxlife - not sure if it is still available in the US- Castrol has one, as does Penzoil, all good choices IMO.

I would recommend some other cleaning product additives but some people regard them as snake oil and that is a whole entirely new discussion. The top end of my engine was varnished up a couple months ago, just opened it up to change a valvecover and it is now spotless, a total 180 degree turnaround and my oil consumption has dropped to almost nothing.

Have you changed your pcv valve in recent years , poorly functioning pcv's can be a problem.

Saki GT

When did you start putting synth oil in? How many miles on the odo?

CapoArgentino

Its normal for AP1s to consume a lot of oil during hard use on the street and track. Stay w/ synthetic and get an good quality, internally baffled oil catch can.

~blacks2k~

How bad is the consumption?

thirstys2k

Saki GT, I bought the car off the original owner who claimed to use synthetic oil "since the beginning" not sure how many miles on the car before he actually started using synthetic. I always ran synthetic oil in the car, so as far as I know it has had synthetic oil in it its whole life.

JFUSION, if the car has been running on synthetic oil its whole life (mostly Amsoil ATM 10w-30) would it really have lots of deposits in it?? I assumed synthetics had a good amount of detergents in it to keep things clean.

Also, do you have a recommendation for a cleaning product additive? Do you mean something like the Lucas upper cylinder lubricator? I've run redline fuel system cleaner, but never anything in the oil if that's what you're referring to.

thirstys2k

^ oh and I have replaced the pcv valve 3 times and each time it did nothing, the last time being about 2 months ago.

Consumes a liter of oil per 3-400 miles. I drive the car very hard, it sees vtec probably 20+ times daily but this is indeed excessive even for that. Weirdest thing is there is no signs of oil burning (i.e smoke, smell etc).

Some people have said bad valve guides, some people say could be piston rings. But i've looked up the symptoms for both of these issues and my car doesn't coincide with any of them, it seems completely fine aside from the high consumption so i'm baffled.

zeroptzero

ah sorry to have misled you then, that amount of oil consumption is very excessive, you have a mechanical issue and there isnt' much that i can recommend that will cure it. You are correct that running Amsoil would keep the engine clean with few deposits. Amsoil 10w30 atm is a great oil, with one of the lowest volatiity burn off numbers of any oil. You have changed the pcv valve without any effect too. A cleaning product won't help you in this case.

I might recommend going to a thicker viscosity oil. I would suggest doing a run of 5w40 and see if it helps, it won't cure your consumption issue but perhaps you can bring it back closer to the standard of 1 quart per 1000 mile threshold. 5w40 is an acceptable weigtht for the s2000 too. I run it in my Ap1 with almost no consumption in 1000 kms so far. You can pretty much use any 40 weight oil though it doesn't have to be 5w40, the 5w40 is nice to have if you drive the car in winter, Otherwise any 40 weight will work.

You definitely have a mechanical issue with the motor, outside of repairing it, all I can suggest is to try a 40 weight oil, conventional or synthetic is up to you. Castrol makes an affordable Syntec 5w40 which might be a good candidate for your car.

I do like running an upper cylinder lube such as Lucas UCL in the fuel, as it can lube items that are in the flow of fuel that don't normally get lubricated by oil splash, things like valves and valve guides, and the tops of piston rings, so it might be worth a try too. These are just some cheap things to try, if they don't work you aren't out too much. They aren't going to solve your issue completely, but if you can get the consumption back down to 1 quart per 1000 miles then you are back down to what might be considered accpetable. If you can get it down to one quart per 1000 miles then you would be doing great and it could still be a mechanically sound engine.

Oh, and try to hit VTEC less than 20 times per day, that will definitely lower your consumption. lol.

hypforlife32

yeah that is alot of oil burning. my ap1 burned royal purple alot and then i switched to castrol gtx motor oil and now i barely burn anything. i am very strict on my oil changes every 2500-3000 miles.

CapoArgentino

Its all about driving style, ambient temperature, distance and overall condition of the engine. In other words, the oil has really not much to do with the consumption, specially since almost all synthetic oils have the same flash point temperatures in the same weight range.