Honda D Series Forum banner

20W50 and STP/Lucas treatment = Too Thick Oil?

3464 Views 11 Replies 7 Participants Last post by  Slow-D
I have a d15b2 and I am currently trying to slow its oil burning down as much as I can. I already have cleaned the PCV valve and changed my oil from the factory specified to 20W50. This made a noticeable difference but it still burns allot of oil. I am eventually going to get the valve stem seals replaced and hopefully that will take care of most of the burning. I am aware that it could be the oil control rings as the engine has over 220,000 miles on it. It smokes a little puff on startup and eventually more as it runs. It gets worst when it revs.I realize that this is a temporary solution I mainly just want to know if 20W50 and Lucas oil stabilizer or STP treatment will actually help or if it will be too thick. Thanks.
1 - 12 of 12 Posts
youre not doing anything to fix the problem. you already know you may need new seals and rings, all youre doing now is making the oil pump work harder on cold starts and possibly causing the bearings to spin
youre not doing anything to fix the problem. you already know you may need new seals and rings, all youre doing now is making the oil pump work harder on cold starts and possibly causing the bearings to spin
Ok thanks.
Valve seals only leak when the guides wear out, which on 88-95 nonVTEC motors starts at about 150k miles.
Valve seals only leak when the guides wear out, which on 88-95 nonVTEC motors starts at about 150k miles.
Thanks for the info. I assume replacing just the seals would be an unnecessary patch job and a waste of time then.
Update: After using seafoam for 100 miles and seafoam spray to clean the intake valves all major oil burning ceased. The engine runs allot better now too.
Still doesnt remedy the need for a full break down and rebuild
You basically have 4 options: keep adding oil and let it die eventually, rebuild the engine, swap the engine, or buy a newer car. Using thicker oil doesn't prevent oil burning as the others have pointed out, you're better off using the reccomended oil
So is redline 40 weight race oil too heavy for track days? They say it's thinner than a real straight 40
Do some testing and find out.

There are some race teams that use 20w-50.

a HOT engine that is being run hard for long periods of time will always enjoy a much thicker oil, since at 250+ F oil temps, that thick ass oil is nearly as thin as standard 5w-30 in a cooler running engine cruising down a highway.

You need to be very cautious and diligent about how you treat cold startups, as its very easy to spin a bearing with thick oil.

Old ford v8s liked to snap distributor shafts when using too thick oil, and Im sure they were more durable then our little shoebox motors.


Best bet is to start with a good quality euro oil like 0w-40, and datalog pressures and temperatures.

do a standard baseline with 5w-30, datalog for a few thousand miles, then try the 0w-40

mobil1 makes a 0w-40 that you can order from any partsstore
See less See more
Still doesnt remedy the need for a full break down and rebuild
Thank you
You basically have 4 options: keep adding oil and let it die eventually, rebuild the engine, swap the engine, or buy a newer car. Using thicker oil doesn't prevent oil burning as the others have pointed out, you're better off using the reccomended oil
Thank you for the input, this was years ago however I agree that a swap or rebuild is the only option aside from a re-ring.
1 - 12 of 12 Posts
Top