Engine oil weight

[nuttyvibe]

Hi guys,I'm going to get my 2nd oil change this week, and I've been contemplating about using Castrol's GTX Start Up engine oil instead of the Valvoline that's used in the dealership. However, I'm confused as to what oil weight I'm supposed to use. Most of the searches I've done here on the forums indicate that 5W-30 is the most popular choice. On my next maintenance sticker in the car, though, it indicates that 10W-30 Valvoline was used in my last oil change.Now my question is:Will switching from 10W-30 to 5W-30 have any significant impact on the engine, either in terms of performance or reliability?Thanks!

[tnpartsguy]

Most modern car require 5W30 during average weather conditions. I use it year round without any problems.

[millster]

I wouldn't say that 5W-30 is the most popular choice, it's just that it's the manufacturer's recommended oil. The fact that your car has 10W-30 in it is a fact that baffles me. How can some mechanics put the wrong weight of oil in these cars? This happened to my Sebring the last time I took it in and it infuriates me. The dealer refused to change it insisting that it made absolutely no difference. Not wanting to pay to have my oil changed again, I decided to forgo returning to that dealer and hope nothing happens.Anyway, I would say go back to 5W-30 and no it should not harm the engine in any way.

[Vibey]

Use 5W-30, that's what GM recommended.

[tnpartsguy]

Quote, originally posted by millster »I wouldn't say that 5W-30 is the most popular choice, it's just that it's the manufacturer's recommended oil. The fact that your car has 10W-30 in it is a fact that baffles me. How can some mechanics put the wrong weight of oil in these cars? This happened to my Sebring the last time I took it in and it infuriates me. The dealer refused to change it insisting that it made absolutely no difference. Not wanting to pay to have my oil changed again, I decided to forgo returning to that dealer and hope nothing happens.Anyway, I would say go back to 5W-30 and no it should not harm the engine in any way.Most dealerships still have 10W30 in the bulk oil tanks. I know ours does, even though Gm went to 5W30 over 10 years ago. Wanna know why? It's cheaper.

[zionzr2]

most "quiky-lube-joints" will put in 10w30 unless you tell them specifically otherwise....EVEN THOUGH THE CAP CLEARLY STATES 5W30.This is why I wish I could do my own oil changes and why I watch like a hawk when I take it in for someone else to do it.I want my own driveway and garage back!!!

[JohnC]

Check the owners manual, i am pretty sure it says 10W-30 is ok if temperatures are not below zero F or so. If you can't get 5w-30.On another note I have been reading about several late model engines that have a problem developing sludge, one of them is a Toyota engine (not ours). The article was in Consumers Reports. If you have one of these engines they recommended using a synthetic.

[03VibeGT6Spd]

Quote, originally posted by JohnC » I have been reading about several late model engines that have a problem developing sludge, one of them is a Toyota engine (not ours). The article was in Consumers Reports. If you have one of these engines they recommended using a synthetic.Using 10w30 instead of 5w30 shouldn't cause any issues, But I'm not 100% sure about these high reeving car engines.I have ran Mobil 1 20w50 in my 1987 4.0L Jeep Comanche year round because it was free, but in the winter it was very very thick.That truck survived it and that was changing the oil every 15,000 miles.Back then Mobil recommend changing there oil every 25,000 miles and a filter at 12,500 miles.About Sludging OilBack in the mid 80's I seen several issues with this and bought a van Cheap with the same trouble.Back then it was the fault of the oil Shell Fire&Ice & Pennzoil.I don't know what oil was used in the van I bought. but after cleaning it out with kerosene, I removed the Valve covers and scrape it out. then removed the oil pan and replace the oil pump and scrub some more.A few more kerosene injection's and several 50 miles oil changes and oil stayed pretty clean.Now the oil companies are blaming it on defective engines, and the Motor companies are blaming the oil companies.I would like to know what oil these engines are running.I agree with the Motor company since I have seen this several times before.The Oil turns into a Heavy grease and gets crusty, and Cakes onto everything it touches. That's one reason it's nice to have an oil pressure gage and not an idiot light.

[rlfreese]

I am a forner zx2 owner now owning a vibe. the zx2 used 5w30 as well, the reaseon that the newer high reving engines use this is that the newer dual cam high reving engines have smaller oil ports in the engine thsu needed a thinner oil to lubricate properly. we tested two zetec engines with two different oils at a zx2 meet. one with 10w30 and one with 5w30 both were valvoline oil. the one with 10w30 had more wear and ran worse and hotter than that with 5w30 after a long day of contuinuous running. that was to prove a point to everyone that when your car calls for a certain oil, use it. it calls for it for a reason. as far as it being cheaper, not true. if you go to advance auto or wal mart a qt of 10w30 and a qt of 5w30 cost the same.

[Vibey]

Quote, originally posted by zionzr2 »most "quiky-lube-joints" will put in 10w30 unless you tell them specifically otherwise....EVEN THOUGH THE CAP CLEARLY STATES 5W30.This is why I wish I could do my own oil changes and why I watch like a hawk when I take it in for someone else to do it.I want my own driveway and garage back!!!My wife's Vibe is a 2003 model and I did the oil change myself this time. I used Valvoline (sp.?) filter and Mobile 1. It took about 20 minutes. The old oil filter and oil got ship to the ECO Station for recycle. The cost was less than the oil changed at one of the fast oil change outlet, and we are talking about cheap oil filter and oil there.

[tnpartsguy]

Quote, originally posted by rlfreese »as far as it being cheaper, not true. if you go to advance auto or wal mart a qt of 10w30 and a qt of 5w30 cost the same.I was talking about GM bulk oil, and yes, the dealer cost on the 10W30 is cheaper. Don't ask me why, but it is. GM has a very long term contract with Mobil on their oil, we just got our 1st price increase in about 2 yrs.

[goodvibe]

10w 30 is perfectly fine down to 0* F. If you lookat the ratings on oil, the first # is the cold viscosity performance and the second # after the w is the true hot oil weight. A 5w30 can be thicker than a 10w30 at operating temps. On cold winter mournings below 0*F a 5w will start flowing easier and give a modest mileaage increase until it's up to temp at which point there is no advantage what so ever. All 5w30s have viscosity improvers that break down and thin the oil. It can also add to sludge production. 10w30 synths often don't need any improvers and in dino the 10w will have less of it than the 5w. If you don't need 5w in your area, you'll be better off with the 10w as it will stay in grade better and sludge less.

[bud_one]

Check this out.....http://www.nordicgroup.us/oil....10W30

[Man of Steel]

Very interesting article. I also clicked on the link for the oil filter evaluation. Not sure if I believe what it says about Fram filters. I've been using them for years with no problems. Does anybody know of anyone who's had problems with Fram oil filters???