QUESTION ON ENGINE BREAK-IN/OIL AND OIL CHANGES... (Page 1/1) eti engineer NOV 16, 09:23 PM As most of you know, I just recently finished my '88 rebuild, engine and rear suspension. I talked to the engine builder yesterday and they will fix the leaking rear seal under warranty. I just need to find a good time to get the car to them. I think the first part of next year as I will be busy for the rest of this year. He assured me they can do it and with a short turn-around time. They have done Fieros before. The question I have is this. According to the builders, I am supposed to use high-zinc oil to allow for proper break-in of the cam, for 500 miles and then drain the oil, change the filter and add another round of high-zinc oil for the next 500 miles. Of course there are restrictions on how the engine should be run, too. But after this second round of high-zinc oil, there are no instructions. Am I good to put regular oil, or a blend, or synthetic oil in the engine at this time? I know that many of you have done rebuilds before and I would just like some information on this. Thanks in advance as usual... Hudini NOV 17, 05:17 AM My opinion (and it's strictly opinion ) Keep using the zinc additive and run full synthetic if you can afford it. You don't need to change the oil every 3000 miles like the old days either. I went with 5000 miles between changes on a turbo engine that wasn't treated kindly. My Volvo's ran 7500 miles between changes on turbo engines. They were treated a little nicer though. If you want to run the cheapest Walmart oil then just change it more frequently but still use the zinc additive. It helps to protect your cam lobes. eti engineer NOV 18, 05:47 PM quote Originally posted by Hudini: My opinion (and it's strictly opinion ) Keep using the zinc additive and run full synthetic if you can afford it. You don't need to change the oil every 3000 miles like the old days either. I went with 5000 miles between changes on a turbo engine that wasn't treated kindly. My Volvo's ran 7500 miles between changes on turbo engines. They were treated a little nicer though. If you want to run the cheapest Walmart oil then just change it more frequently but still use the zinc additive. It helps to protect your cam lobes. Thanks. I am a firm believer in frequent oil changes. On my other vehicles, I have it changed it out every 3-4K miles and I use a blend of synthetic and regular. Does the zinc additive mix well with synthetic oil? I have heard that it doesn't, but have not been able to verify one way or another. This would be my main concern. I used to do my own oil, but now that I can afford it, I let others do it. It's just much easier to have someone else do it while I keep an eye on them through the windows. I dropped SpeeDee Oil Change because they tried to pull a fast one on me. Their worst enemy is someone who is "car smart".