I need to get an oil change next month and will be switching to synthetic. My GS has 103K miles on it and I live in NY.

Temperatures range from -5 (winter) to 105 (summer); what is a good year round oil weight to use?

Do I still use the OEM suggested 5w30 (conventional oil) weight even though I am switching to synthetic?

Also, which name brand is a good one to use? I am thinking about Mobil1 as I have read good things about this type of motor oil.

Lastly, is a flush needed?

Thanks for all the advice in advance!
Nick

 

I would probably stick with 5w30 for the winter and use a 10w30 for the summer.

What kind of flush are you describing? Transmission? Radiator? Brake fluid?

 

the weights between synthetic and conventional oil is the same. If your car runs on 5w-30 before, there should be no reason to switch to any other weight unless your climate is extreme. 5w weight should be good down to about -30 degrees F. You may try 0w-30 if you like for those harsh winter times, but I doubt you'll need it. For the insanely hot summers, you can try 40w as 30w will be reaching near its peak performance around 105 degrees.

 

Castrol <-- Big with the BMW community. I used to use in my M3
Mobile One <-- Very reputable company and have been using for years

They both make high mileage formulas.

 

i use FULL synthetic valvoline oil 10-30 year round with a mobil one filter. i had been using full mobile one synthetic but i have a buddy who works for valvoline and i get my full synthetic oild change for 40 bucks so i sacrifice but i wont on their filter!

 

Eh, I'd avoid the Mobil1 filters... overpriced and not worth it. OEM filters are pretty damn good. As far as oil goes, stay 5w-30. Castrol, Mobil1, Amsoil are all good with Amsoil being a few steps ahead. You can send in a UOA to blackstone labs and see the results yourself. Just get some of the used oil mid-drain and send it in for analysis. Engine "flushes" are unecessary... its often just running some kerosene-like product (gumout) ect through your engine... If you want, add some Seafoam to your Oil along with doing the usual seafoam treatment by sucking some of it in through a vacuum line (PCV or brakebooster) and drive around with in in there for a few miles before your next oil change. Just don't leave it in there all week. If you need any help, LMK, i'm roaming all over NY these days.

 

....Great! Thanks for the advice guys. I will stick with a 5w-30 weight and probably go with Mobil1 or Amsoil and utilize the OEM filter.

dj...I'll hit you up if I decide to do this myself. I was thinking of just bringing it to a shop though; we'll see. Thanks

 

i would go 0w30 if you are one of those people who just starts it and does not let the engine warm up properly

 

That's what I use and a Castrol 0W30 at that. That's probably not too bad of an idea at 103K, as even though it is a 30, it is actually more similar to a 40. Autozone and Pep Boys sell this fine oil made in Germany.

 

I haven't been able to find German Castrol in any Autozone or Pepboys in NY and I've looked across several counties.... last time I used 0w-30 the only thing I noticed was excess oil consumption... I'd stick to 5w-30 since synthetics don't thicken like conventional oils in the cold... or at least thats what I've been told...

 

It's a hit/miss thing. When I lived near Tampa (Bradenton, Florida), I found that Castrol there. A friend of mine uses that same oil in his Z06.

I never had an issue with the Castrol 0W30, even when I still did 1/4 mile racing with the RX back in Mexico.

For a 5W30, I'd take Amsoil. But if I couldn't find that, I'd take Pennzoil Platinum 5W30 over Mobil 1 5W30 any day. I ran into consumption problems with 5W30 M1 down in Mexico. The only thing I could find in a M1 that did a decent job (and even then I had to use some additives) was their 0W40.

 

I too use pennzoil over Mobil 1. I find that I burn a bit more oil with M1 than Pennzoil. Plus pennzoil is cheaper for me so that's a big plus. Never will I go back to M1 unless they have some kind of crazy discount.

 

How much does Pennzoil run? I usually just buy M1 at wal-mart

 

It's pretty much comparable in price, sometimes a bit cheaper. I think WalMart had the cheapest price on the Pennzoil Platinum over AutoZone and other places.

 

I went to walmart the other day (one in Westminster, the other in Cerritos) and neither of them had M1 in stock AT ALL. But the price for the 5qt jug was $26. Months ago, they were on sale for $22 or so.

Pennzoil is cheaper if you buy individual bottles. They're $4.01/quart around here so you're saving about $6.