John Scott Posted May 13, 2003 Share Posted May 13, 2003 I've heard and seen the more prone to leaking of this expensive motor oil, but oil consumption? 15/ 50 was on sale at the local target and after hearing recommendations, decided my engine was worth having the "good stuff". 100 miles and a quart short. Topped it back up, looked underneath. A few more drips, but no real concern. 100 more same result. Vacuum guage test said guides were sound on my new AFRs. Don't have a leakdown tester. Drove it really hard and it gobbled another quart in well under 100 miles. Visited another couple of forums and found there might be a correlation to rings not seating with the Mobile 1. Dozen or so pulls on the engine stand with the original Vavoline, then 100s of miles actually driving on the mobile 1. Switched back to my builders recommendation of 20/50 Vavoline and magically, no consumption what-so-ever. I never saw blue smoke under power, the underside is pretty clean, where did the Mobil 1 go? Should I go back after a few more thousand miles? John Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted May 14, 2003 Share Posted May 14, 2003 I think your consumption may have more to do with the slightly lower viscosity of 15W-50 vs the 20W-50. It is not much, but it still may be significant enough to come past the rings. Synthetic oils are not typically "slipperier" than conventional oils, they just have better tolerance to oxidation due to heat and also flow better at low temperature. Synthetics are also designed to be a multigrade oil without the addition of viscosity improver polymers. These polymers are needed in conventional oils to achieve high temperature performance. After time these polymers shear down and what started out as a 20W-50 will eventually become a 20W-40, or less. A good test of my viscosity theory would be to find a synthetic 20W-50 and see if comsumption changes. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted May 14, 2003 Share Posted May 14, 2003 I have known other people who have given up on synthetic oils for the same reason. Their cars drank up the synthetic but not conventional oils. The viscosity might have something to do with it, but I know both of my cars run fine with the factory recommended 5w-30 (or is it 10w-30?). Either way much thinner than a 15W-50. I have read that you are not suppose to break in a car with synthetics. Anyone know if this is true? But my buddy's car had 20K miles when he first tried synthetics, so there is something else going on. I think there is an issue with synthetics. I am curious to hear whether anyone else had consumption issues with synthetic oils. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted May 14, 2003 Share Posted May 14, 2003 Same problem with my ZXT. Changed to 10W30 Mobil one and seem to have to top it up more often. Gets expensive with the 'good stuff'!! Tim Quote Link to comment Share on other sites More sharing options...
Synlubes Posted May 15, 2003 Share Posted May 15, 2003 Yes, A good 5,000 mile breakin period is a good number. I also would recommend (using non-synthetic) changing oil and filter at 100, 2500 and 5000 miles after a fresh motor. Then go with some synthetic lubes. I personally change oil and filter after the first run(30 min), then at 100, 1000, 2500, 4000 miles on my freshies. Then I install my synlubes. I have not, nor have I had any customers with oil consumpions problems. Even the cars with higher mileage before doing lube changes. I think alot has to do with breakin procedures, crappy rings, cly wall condition or it wasn`t put together just rite from the get go(ie factory). Quote Link to comment Share on other sites More sharing options...
yo2001 Posted May 15, 2003 Share Posted May 15, 2003 No problem with 10w30 Mobile 1 in mt turbo either. But with stock T3, the turbo was smoking some oil. Darn 270 deg thrust bearing I'm going to order the AMSoil soon Doug. I swear. Quote Link to comment Share on other sites More sharing options...
fl327 Posted May 15, 2003 Share Posted May 15, 2003 i run 10w-40 syntec, just burned a qt of it the first 1000 miles, but im leaking some as well from somewhere, but i like it. 1000 more to go and then we'll see what oil to gowith i guess. Quote Link to comment Share on other sites More sharing options...
denny411 Posted May 15, 2003 Share Posted May 15, 2003 I use mobile1 5w30 in my wifes explorer and have had no oil usage whatsoever. Even when I pulled the boat to Alabama, it was still on full when we got there. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted May 15, 2003 Share Posted May 15, 2003 I know after reading some posts from Grumpy, that he recommends using a mineral based oil for the first 2 oil changes(inital break-in, and 100 miles) then change over to the "good stuff." Thats what I'm going to do for my fresh LT1. I'll have to let you guys know how things go. I'm just waiting on my driveshaft so that I can go get the exhaust done! Then its break-in time!!!!! Guy Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted June 9, 2003 Share Posted June 9, 2003 I put about 2800m miles on my 2000 Silverado, and then switched over to Mobil 1 5w30 synthetic, and I change it when the computer tells me to, and I am not using any that I know of. I just started using the Castrol Syntec in 10w30, and I swear I get better mileage with it then Mobil 1. I have never been able to keep synthetic in a Z motor, but I know keeping the rev's under 3k when driving helps with oil consumption. Turn it over 3k, and watch it go bye bye. Quote Link to comment Share on other sites More sharing options...
BusterZ Posted June 10, 2003 Share Posted June 10, 2003 Yeah, break in on conventional motor oil. You need the wear to seat rings, etc. Synthetic base stocks are more stable and do not degrade nearly as quickley at higher temps. They also have less change in viscosity as the temperature changes (higher viscosity index, vi). Some newer motor oil base stocks are hydrotreated (saturated with hydrogen) to increase the vi which gives a more stable viscosity. I've run Mobil 1 in most all my engines (after break in) and have not seen increase in consumption or leakage. Syntec has a hydrotreated base stock. I use Castrol conventional motor oil, they use a very good additive package in their oil. Remember, auto manufactures want you to run the lower visc oils (5w 's) to get better fleet mile per gallon numbers (not intrested in engine life). I've never run below a 10w- oil and had no problems. PS I keep most vehicles atleast 10 years and usually well ovewr 150000 miles Quote Link to comment Share on other sites More sharing options...
johnc Posted June 10, 2003 Share Posted June 10, 2003 On my 2000 Ford F350 with the 6.8L V10 I see a slight increase in oil consumption running Mobil 1 10W-30 over the dealer installed generic 10W-30. I've done back-to-back checks (dealer does free oil changes for life) for 5,000 miles intervals and noted about a 1/2 quart difference in usage. Regular oil requires adding 1/2 quart in that mileage period and Mobil 1 needs 1 quart. On a cold start I will see a puff of smoke when the truck is running Mobil 1 and I won't see it when using regular oil. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.