I have tried a variety of 10/30 synthetics and all are good except for the walmart brand. Mobil, castral, all a few others I've tried make my average fuel economy read out jump 1/2 mpg within 10-15 minutes of driving. The walmart brand made no difference to fuel economy.A1/2 mpg (or 5%)improvmentpays for the higher cost of oil.

 

I use Shell's Rotella T regular in all my vehicles with cats and Rotella T syn in my bikes and vehicles w/o cats. Just as good as the above butwith much less $$$.

 

i cant account for the motor oil (yet)

but i use their MAX-ATF and it works great.

 

I use the Amsoil 5-30w in the engine, synthetic gear oil front and back, and synthetic tranny oil in trans, transfer case and power-steering pump.

 

Now that's what I'm talking about.

Also replacing maybe a pint of amsoil, with a pint of marvel mystery oil. Had to throw it in there. That stuff really is magic (unlike criss angel who is a fake)

 

Thats a proven myth. Switching to Syn. doesn't make it leak or burn oil.

 

i run Mobil 1 10w30 in all my vehicles in the warmer months, usually put in 5w30 in the freezing months. with it being synthetic though, it probably doesn't make much difference on cold startups.

here's a little story why I'll NEVER use Pennzoil in a vehicle. i acquired a 92 bonneville with 189K on it about 18 months ago, the owner had used pennzoil 10w30 in it for it's entire life. First thing i did was drain it & put in mobil 1 10w30 (4.5 qts.). about500 miles later i checked the stick to see if it was using any, and to my surpriseit wasa little OVER the fullmark.Coolant levels hadn't moved &the oillooked ok so I just blew it off, figuredmaybe i had added all 5 qts.instead of the4.5.Another 1,000 miles and I check it again, this time it's WAY over the full mark. I figured for the worst at this point, drained the oil into a clean bucket so i could look closer for coolant/metal shavings/etc... None of that stuff came out, just 5.75 NASTY black qts of oil. The synthetic had loosened up all the sludged on pennzoil crap that had accumulated over the years.over the next 10K milesand 3 more oil changes that sludge kept coming out. The last oil change I did on that car before I sold it the oil had come out just slightly darker than the new oil i put in.

 

I would definitely try amsoil or mobil 1, it's just that itch for the Royal Purple oil has been nagging me since I found dragsters using it in their muscle cars (keep in mind my original baby is a 1975 Chevy Nova, and i'm 20 so it's not like i grew up with them being new, lol). I want to drain all fluids and replace it with Syn. RP stuff. The block runs fine, but it seems it's just old blood in there, and I have no way of knowing it the stuff in there is 4 weeks old, or 5 years old. Nothing is black, so it's ok for now. Just waiting on more recommendations on viscosity level to put in.

 

I switched my 2000 gasser to mobil 1 15w50at 121k miles (when I got it) and never had a leak... sold it with 185k on it and still no leaks.

 

I had the same thing happen after I read up on oil a couple of years ago. I used to run dino oil and switched to mobil 1 extended mileage and ran it for 10K with an extended life oil filter. When I dumped it,theoil was BLACK. Not a shiny sleek black, but a dull, devoid of all light, can't see my fingers with athin coat of oil on them black.

I got lucky I didn't have a problem.