I just dropped a new motor in my 99z and have been running conventional house brand oil for the break in period. I ALWAYS ran synthetic oil in the previous motor, religiously (mobil1 10w30). I know that this is more of a personal preference kind of thing, but I've had a lot of guys tell me they have always ran a a conventional valvoline in a high horsepower engine and never had any problems (they also said that they change it as soon as it starts breaking down, usually on or before 3k). Other than the obvious perks of longer oil life, is it a must to run synthetic? vehicle mods are as follows: LS6 block and heads, stock crank/pistons/rods, MS3 compcam (237/242, .603 .609 on a 112 LSA). I ALWAYS run 93 octane and even when i was running full synthetic in the motor i usually changed it around 3500 miles.

 

After your 1500 mile or so break-in period on the new motor, I'd switch to a full synthetic.

Mike

 

It is not required. Most people will use it though.

 

No. I've been building LS1's for 10 years, and I never use synthetic oil. Valvoline or Penzoil work just fine and half the price.

 

Not a must. I believe in synthetics as far as reconditioning seals,etc goes. I got my LS1 last winter and I had an slight oil leak ..Since I have done 3-4 oil changes all w/ %100 synthetics...guess what no more oil leak. Thats all ill put in my car...If you do it yourself the oil is only 5-10 bucks more depending on what brand your buying, so why not.

 

Since the first oil change on my '00 Z28, I've used Mobil 1 synthetic. After 108K miles, I've had no engine problems & no sludge. I think if you switch to synthetic early on, you won't experience any of the leaking issues that a few people have had.

 

My question is this, what Mobil 1 oil should I use on my 2000 and what filter ? How many quarts does the LS1 hold ? I'm wondering all this because I'm switching over to synthetic. My car has 55K miles on it..

 

5w30. 5.5 quarts, some people just use 6...I always use an AC Delco PF46 filter...cheap and one of the best around...Mobil 1 isnt what it was years ago...Ive used amsoil, mobil 1 extended performance, qhorsepower, and penn. platinum and they have all be good.

 

Antz97ZNJ

Thanks for the help!

I was looking at the 5w30 Mobil 1 and they have one kind that says nothing and one that says "ESP Formula". Does it matter ? which should I get ?

 

Never mind, it's emission system protection.. I'll just get the regular 5w30.

 

I would run the synthetic.

The main benifits are usually improved wear, better cold startup flow, better additive package, runs cleaner, and better resistance to breakdown.

The biggest drawbacks I hear about are cost, and not to switch in an old motor; and not to run it when a motor is new.

as far as running it too early or late, Ive never seen issue's with that 1st hand. Quite a few new cars come with synth as the factory fill. and as for synth in an old motor, maybe. But it seems all the horror stories about that are from way back when synth was in its infancy. I could see old-tech carbed motors that run dirty having issues with sludge getting cleared out and causing problems, or old seals starting to leak. with new motors, modern seal construction, and todays clean running motors, it probably is less of an issue.

Cost, well it does cost more. BUT, on a site dedicated to lubricants (BITOG); people that do oil analysys show that they can usually go 7000-15000 miles between changes. with no loss of performance or additional wear. I personally dont go quite that long, but stick to 5000 mile changes w synth. The BIG reason is that with 3 cars, I only drive each one at most 5K a year. So, I change each yearly. Soon enough.

Stick to a major brand synthetic (brand vs cost, your choice). and be happy. Ive used to run mobile 1, but after horror stories with 2.0 wrx motors and that oil, Ive been running valvoline. PLUS they claim to give me a 300K engine warranty if I do so. Not too shabby.

 

if you push your synthetic to 7k like i do, using a new oil filter at 5k, and topping it off every re-fuel (BTW a bottle of mobile 1 fits perfectly behind the headlight under the hood, call me redneck but its freakin handy right there) then using synthetics is actually the cheaper way to go. in the long run you'll do a couple fewer oil changes and save money.

and dont freak when you see dark oil at 5k after a filter replacement, its still holding up just fine.

 

Oil is dark 30 seconds after you fire the engine I bet

I recommend synth just like everyone else.

 

The filter is plenty capable of going 7k miles with your oil. Some cars now only call for a filter change every other oil change. The wife's Honda Element requires an oil change every 10k miles and filter change every 20k miles.

 

That's probably because they use a canister-type oil filter. My BMW is the same way. 15,000 miles or 2 years for an oil change. I'll still change it at 5000 though