Killtodie Posted July 13, 2009 Report Share Posted July 13, 2009 So should I stick to 20w50 what I was originally recommended here or go a little lighter like 10w30 which is what the tech at Royal Purple recommended. Link to comment Share on other sites More sharing options...
on4now4 Posted July 13, 2009 Report Share Posted July 13, 2009 i use Valvoline vr1 20w50 works great Link to comment Share on other sites More sharing options...
BrazilBoy Posted July 13, 2009 Report Share Posted July 13, 2009 go 10w40 synthetic since the oil runs through the turbo.....I like Valvoline Racing 10w40... I have always run 20w50 and even straight 50 in my built cars...but the conquest seems happier with the 10w40 Link to comment Share on other sites More sharing options...
Killtodie Posted July 13, 2009 Author Report Share Posted July 13, 2009 Hmm, different opinions What are these cars designed to run on? And what is best for me to use year round for Chicago weather? Link to comment Share on other sites More sharing options...
Whiplash Posted July 13, 2009 Report Share Posted July 13, 2009 Go with the 10W30 Royal Purple! Link to comment Share on other sites More sharing options...
Tim_C. Posted July 13, 2009 Report Share Posted July 13, 2009 Hmm, different opinions What are these cars designed to run on? And what is best for me to use year round for Chicago weather? Yeah, year round is better to go with the 10/30 (choice between 10/30 and 20/50 if it ever sees cold temps. However, you can go 20/50 with no problems too. It might just take a few more minutes to warm up. I use 15/40 in my daily driver '83 Starion. It tends to last longer and not burn off quite so fast. It is also a happy medium between 10/30 and 20/50. Link to comment Share on other sites More sharing options...
Killtodie Posted July 13, 2009 Author Report Share Posted July 13, 2009 The RP guys says that heavier oil decreases MPGs Link to comment Share on other sites More sharing options...
88TSI_Rob Posted July 14, 2009 Report Share Posted July 14, 2009 It does, but the difference is minor. Stay out of the boost alittle more and you'll never notice. Really the only penalty to using a heavier weight oil is a slight loss of MPG. The penalty to going too light is much worse. Possible engine wear up to something as bad as a spun bearing in the worse case. Keep in mind that the G54B was designed back in the '70's. Tolerances weren't as tight back then as they are with today's modern engines & light weight oils. It's best to stick pretty close to the manf. recommendations. I personally use 15-40 in the summer, 10-40 in the winter. A 30 weight oil is a little too light for my taste. Link to comment Share on other sites More sharing options...
Dad Posted July 14, 2009 Report Share Posted July 14, 2009 I run 5w30 lately 25-30 lbs hot idle 85lbs @65 mph hot. Dad Link to comment Share on other sites More sharing options...
vbrad511 Posted July 14, 2009 Report Share Posted July 14, 2009 I switched to Mobil1 in my car and truck several years back. I run 15/50 in both in the summer, then drop the truck to 10/40 in the colder months. I stay with the 15/50 in the car, and it's never given me any problems starting even in the negative temps. Maybe it's because the motor's about worn out, lol. Link to comment Share on other sites More sharing options...
Edde Posted July 14, 2009 Report Share Posted July 14, 2009 10/30 Link to comment Share on other sites More sharing options...
nathan89quest Posted July 14, 2009 Report Share Posted July 14, 2009 I run rotella 15/40 year round, but my car is spoiled it hasn't seen snow aslong as I've owed it. I also have a heated garage to tho. Link to comment Share on other sites More sharing options...
ucw458 Posted July 14, 2009 Report Share Posted July 14, 2009 The factory service manual reccomends 10w-30 for most climates between -10 to 120 degrees F For cold climates (60 to -20 and colder) 5w-30 20-50 is too thick. Especially on cold startups. Remember using an oil that is too thick can have bad consiquenses. You have a bypass valve in your oil filter that allows some oil to bypass the filter element when it's cloged or the oil is cold. Running an oil that is too thick will open that bypass more and allow more if not most of your oil to bypass the filter. Meaning with thicker oil you will get more unfiltered oil in your engine. Does that sound good to you? I have run 10w-30 in all my cars. My trucks, my V8s, my turbo cars, all of them. I have never had a problem with the oil being too thin. Link to comment Share on other sites More sharing options...
Komeuppance Posted July 14, 2009 Report Share Posted July 14, 2009 Mobil1 Synthetic 15w50... FTMFW. -Robert Link to comment Share on other sites More sharing options...
psu_Crash Posted July 14, 2009 Report Share Posted July 14, 2009 Mobil1 Synthetic 15w50... FTMFW. -Robert x2 Link to comment Share on other sites More sharing options...
JohnnyWadd Posted July 14, 2009 Report Share Posted July 14, 2009 (edited) So should I stick to 20w50 what I was originally recommended here yes go a little lighter like 10w30 which is what the tech at Royal Purple recommended. no. he is trying to sell you oil you dont need. 20 years ago 10w30 was fine but your motor has a lot of wear on it now and it runs hotter than most engines wich means the viscosity is automatically lowered anyway. 20-50 is too thick. Running an oil that is too thick will open that bypass more and allow more if not most of your oil to bypass the filter. Meaning with thicker oil you will get more unfiltered oil in your engine. Does that sound good to you? doesn't our bypass work on temp? i thought the oil cooler was bypassed until it got to a certain temp and then it went through the oil cooler? i didnt know the oil filter was bypassed. Edited July 14, 2009 by JohnnyWadd Link to comment Share on other sites More sharing options...
Killtodie Posted July 14, 2009 Author Report Share Posted July 14, 2009 wow, no one here can agree on any one weight. Link to comment Share on other sites More sharing options...
scott87star Posted July 14, 2009 Report Share Posted July 14, 2009 wow, no one here can agree on any one weight. Nope, and never will. A couple of us are running 0/30W without issue and I use oil analysis to monitor for wear and there isn't any. I drove my Starion from Houston to Branson, Mo for the Nationals and then up to Grand Forks, ND across Minnesota and back to Houston, sitting in heavy traffic on a 99 degree day for the last hour. About 4000 miles, no wear. I personally think heavy oils are a bigger danger in that they don't pump as readily, thinner fluids pump faster and as long as you can maintain the kind of pressure that Dad posted above there should be no problems. Scott Link to comment Share on other sites More sharing options...
Edde Posted July 14, 2009 Report Share Posted July 14, 2009 Just put some oil in the freezer for a night and see what it looks like the next day. 20/50 hardly moves on cold starts in the winter. Link to comment Share on other sites More sharing options...
Killtodie Posted July 14, 2009 Author Report Share Posted July 14, 2009 Well its hot now. I'll drop down for a lower weight next oil change. Either 10w40 or 10w30. btw, how long do people go no a single oil change? I'm using Royal Purple. Should I pull at least 5k miles? Link to comment Share on other sites More sharing options...
Edde Posted July 14, 2009 Report Share Posted July 14, 2009 Dunno I've never seen RP but when it smells like fuel - dump it. Link to comment Share on other sites More sharing options...
Starfighterpilot Posted July 14, 2009 Report Share Posted July 14, 2009 (edited) Actually what weight of oil to use in Starquests is like asking 20 guys which of 5, No. 10 women is the most beautiful. You will probably get around 4 each voting for each of the women. All I can say is what has worked for me the past 21 years with my Starion which has about 300K miles on it running the ORIGINAL OEM oil pump, but the plunger and it's spring has been replaced. The short block has never been apart, except when I changed, when I did not have to, the rod bearings when I did the BSE back in '05 at 220K miles. (They showed very little signs of wear.) I've got between 130 to 133 PSIG compression across the four pots, and oil pressure is the same as when she was brandy new. At least it was until my oil pressure sensor went out about a month ago. (I check engine oil level everytime before I start the engine since that sensor went out.) I'm ordering a new one through JAHJAH today. I have used Castrol 20W-50 in the late Spring to early Fall and 10W-40 late Fall to early Spring, since the dealer oil changes when she was new. I RELIGIOUSLY change the engine oil between 2000 to 2500 miles. Every oil change, I replace the oil filter with a NAPA 1381 Gold oil filter. I run the 20W-50 during the warm to hot months, cuz that turbo housing gets pretty damn hot under certain conditions, and I want to give the turbo bearings/oil seal as much help as possible during those conditions. Even though tests have shown that synthetic oil is SOMEWHAT superior to "natural" oils, I shy away from them because the G54B Turbo engine was not designed for it. Plus if the engine has used "natural" oils it's whole life, I have heard of and seen many instances of the engine suddenly developing oil leaks where there were none before after the synthetic was used. BTW - About 2 weeks ago, I was VERY glad that I had the Castrol 20W-50 oil in her, when traveling from Atlanta to Tulsa when she was running at 75 - 85 MPH, with the AC on, in about 105 or higher DEG temps outside, in Arkansas. The engine temp, with a radiator which has just been rodded out 4 months ago, was running about an eight of an inch above the dash's temp meter's middle mark. Granted that the Starquest Shop Manual shows using 20W-40 engine oil - 20W-50 engine oil did not come out for a couple of years AFTER that generic to all '80's MITSU personal vehicles, Maintenance Section was written in the very early '80's or late '70's when they teamed up with Chrysler and MITSU had to write the shop manuals in English. 20W-40 engine oil was the heaviest weight multi-weight engine oil available at the time that section was written. There is another thing that you guys should be aware of - the American Petroleum Institute's (API) Service Category. It is not really a issue if you buy your oil from an Auto Parts Store, however, there are different API Service Categories for the same weights of oils. And those dramatically effect the performance of the oils under various operating conditions/applications. For instance, when I worked at Komatsu Forklift, we used 3 weights conforming to various API Categories of engine oil for various forkfts under various uses. Castrol 20W-50, API Service Category SM, was used on the big forklift turbo-charged engines (Toyota inline 6 bangers), indoor and/or Summer outdoor use; and 10W-40, same API Service Category for outdoor Winter use; and Komatsu "Genuine Engine Oil," 15W-40, conforming to API Service Categories CI-4/SL, CH-4SJ, CF-4, CF-2 and CF were used in the medium to small sized forklifts, with inline 4 bangers, primarily indoor use. I forgot what we used on the outdoor Winter use, and I do not have a jug of it anymore. I recommend the Castrol or Valveline brands. I can't remember which, but either Pennzoil or Quaker State develops more sludge in the engine than other brands. But what weight/brand of oil to use is up to you. You pick out the "most beautiful woman" and go for it. For What It's Worth. KEN Edited July 14, 2009 by Starfighterpilot Link to comment Share on other sites More sharing options...
BrokenquestTSI Posted July 14, 2009 Report Share Posted July 14, 2009 i use 10w-40. should i switch too 10w-30? Link to comment Share on other sites More sharing options...
Starfighterpilot Posted July 14, 2009 Report Share Posted July 14, 2009 i use 10w-40. should i switch too 10w-30? Why would you want to go to 10W-30? Have you read the Maintenance Section of the FSM for weights of oils for different operating enviroments? Read my above post and pick out the "most beautiful woman." For What It's Worth. KEN Link to comment Share on other sites More sharing options...
Killtodie Posted July 14, 2009 Author Report Share Posted July 14, 2009 (edited) I heard about going from regular to synthetic might cause leaks but never actually heard of it happening. Its almost recommended just in case to go half synth half regular before making the switch. But RP says you can pour that s*** in on a high mileage car and no damage will occur. Why do you change your oil so often? I take my Civic to 7500 on RP, before I used to go 5000 but after skipping one and checking regularly on the oil I saw no difference in the extra 2.5k miles VWs for example say 10k miles in the manual on regular oil =) Edited July 14, 2009 by Killtodie Link to comment Share on other sites More sharing options...
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