I've always used Mobile 1 5w-30, but if you look under the hood you can see it states 10w-30 for warmer temps and 5w-30 for the cooler temps. However once an engine gets some higher mileage on it, it's better to use the thicker stuff. Hope this kinda helps?

 

Hope this kinda helps?

yea its a lil encouragment i reckon

 

Why is thicker oil better on older engines?

 

Because of things like worn rings...The thicker oil won't squeeze past and burn in the combustion chamber. Also, small leaks might not leak with thicker oil.

It's not a bad idea, but check it a lot the first time out, and make sure everything is kosher.

 

I've always used Mobile 1 5w-30, but if you look under the hood you can see it states 10w-30 for warmer temps and 5w-30 for the cooler temps. However once an engine gets some higher mileage on it, it's better to use the thicker stuff. Hope this kinda helps?

Just remember that 5w-30 is only thinner when the engine is cold. It's got the same viscosity as 10w-30 when the engine is at operating temperature. Most engine wear is happens at startup on a cold engine.

Personally, I wouldn’t use thicker oil then the manufacturer recommends, but that’s just me.

 

here in phoenix, alot of us use 20-50 in the summer and 10-40 in the winter, in my 350 i use 20-50 all year round but was told by my builder to use 30 all year round instead.... in a high mileage car where the ambient temperature isnt too big a deal like it is here, id say 10-40 would be just great... just dont have a brain fart and use some synthetic stuff.... you'll be sorrrrrrrry. btw, i use castrol, just my personal favorite, what kind are you using or contemplating using? just curious...

 

I used 5w-30 in my 145 K engine !!! Use a thicker oil ONLY if you are sarting to burn oil !!!

 

I used 5w-30 in my 145 K engine !!! Use a thicker oil ONLY if you are sarting to burn oil !!!

i meant to say that too.... very true, unless you are burning oil, why are you worried?

 

All this talk about oil.. just when I was thinking to myself "hmm I should ask the Altima god's about it"

Is it okay to do a direct switch over to a synthetic oil from a normal one?

I recently bought my car used, and I have no past info on oil types used etc. It has 123xxx km's on it. The dealership put uhhh Castrol 5w-30 in it, I believe, not too sure cuz the sticker is in the car. Should I drain it out and replace the oil filter and throw in some Mobil 1 Synt or something? Any thoughts?

 

NOOOOO!!! another so-called rule of thumb... when you have an engine over 50 g's, dont use synthetic. by this time you have sludge and other gunk in your seals thats keeping oil IN the engine. synthetics have a high volume of detergents in them that will remove those deposits and make you leak like a sieve. one thing about syn oil is that you would never have to change it if it wasnt for dirt and carbon and other by-products of combustion, it doesnt break down like fossil oils do, it just gets dirty, but no, dont risk it...youll be replacing seals soon if you do....

 

I use 10w30 Valvoline Maxlife year round... I have 135k miles. I would also not recommend synthetic unless you are already using it with no problems. MANY people on here would disagree with me about switching to synthetic, but a few of us have had problems. I started to leak in about 3 places and burned oil. I switched to the maxlife after that. I have a slight drip from my rear main now, and haven't noticed any oil burning. If you think I'm kidding... I can scan and post the letter I got in the mail for being reported by someone as a "smoking vehicle"

Demmy

 

I use Mobil 1 in all 3 of my cars. I switched over, cuz they were all used, as soon as we got them. No problems what-so-ever. My Altima has been trouble free for over 80,000 with synthetic.

 

if a car has been on synthetic from the get-go or a under 50 g's you probably will never have a problem with syn, thats not what i meant. and i truly believe that some oils are much better than others no matter what the ratings on them are. i only meant that if you have a high miler that has NEVER been on syn, then you will, ill say 90% of the time, have leak problems if you change it over.

 

I got my $300 Maxima with 180,000 miles on it, and it burns oil, so I tried switching over to Mobil 1, and it burns less, and doesn't leak a drop. So, guess it's not as bad as you think.

 

well, actually thats explainable, synthetic oil DOESNT burn, thats a fact. the leaking part, well, maybe the guy before you took really good care of it, there is always an exceptiont to every rule, maybe you got lucky like i did, ive got a 94 that i picked up with only 115 thousand on it....with no leaks also, so i guess we all just get lucky once in awhile...

 

I got my $300 Maxima with 180,000 miles on it, and it burns oil, so I tried switching over to Mobil 1, and it burns less, and doesn't leak a drop. So, guess it's not as bad as you think.

I switched with almost 75 I think and haven't burned a drop or leaked any.

 

NOOOOO!!! another so-called rule of thumb... when you have an engine over 50 g's, dont use synthetic. by this time you have sludge and other gunk in your seals thats keeping oil IN the engine. synthetics have a high volume of detergents in them that will remove those deposits and make you leak like a sieve. one thing about syn oil is that you would never have to change it if it wasnt for dirt and carbon and other by-products of combustion, it doesnt break down like fossil oils do, it just gets dirty, but no, dont risk it...youll be replacing seals soon if you do....

HMM I disagree , I did the switch at 135 K , with no problems , yea it could cause oil leaks but only if the seals are in bad shape and or leaking anyways !!!!

 

I switched over at 98k and only had one prob, whenever i pull out plug #1 from the left it allwayys has oil on the elctrode. So this weekend im gonna change all the gaskets and se if that fixes it. But besides that ive had no prob.

 

i'm somewhat afraid to switch, and dont really feel like givin nearly $3 a quart for oil....sense im a college student... *im broke* So still do u guys think its bad idea to run 10w40????????? im only thinkin about it.... i'll prolly just stick with 10w30---- hehe

 

HMM I disagree , I did the switch at 135 K , with no problems , yea it could cause oil leaks but only if the seals are in bad shape and or leaking anyways !!!!

Wow, someone who understands the high mileage thing is a myth. Cool. I wish more people would understand that switching over at high mileage is not the problem, though the odds are better with the more mileage you have that you will develop a leak.

 

Personally I don't think the odds are worth the bet.

Demmy

 

not to toot my own horn, but before i became the helicopter technician extraordinaire that i am, hehe, i WAS an auto mechanic... when the first synthetics came out, that was and is, the big problem. too many conventional oils have paraffin and other ingredients that create sludge and other oil trapping deposits in an engine. so yes, odds or not, high mileage changeovers are not a good idea. though i will say like i said earlier, some people get lucky, they are able to acquire a vehicle with and engine that was taken care of.

 

some people get lucky, they are able to acquire a vehicle with and engine that was taken care of.

key word lucky...im not lucky with cars!!! im sticking with mineral oil!!

 

not to toot my own horn, but before i became the helicopter technician extraordinaire that i am, hehe, i WAS an auto mechanic... when the first synthetics came out, that was and is, the big problem. too many conventional oils have paraffin and other ingredients that create sludge and other oil trapping deposits in an engine. so yes, odds or not, high mileage changeovers are not a good idea. though i will say like i said earlier, some people get lucky, they are able to acquire a vehicle with and engine that was taken care of.

Key phrase=when the first synthetics came out, that was and is, the big problem. You're talking about technology that is almost thrity years old. A lot has changed in the formulations since then. Just look at Mobil 1, they have reformulated 3 times in the past five or six years.

The issue with the seals when synthetics first came out occured because conventional oils have the natural ability, due to the aromatic compounds, to to promote seal swell. The first synthetics did not have these properties "built" into them, so when their greater detergency cleaned out the gunk the conventional oils left behind, the seals would dry up and crack. Fast forward to today, and synthetic oils incorporate compounds that promote seal swell. The only leakage issue occurs when the seals are already so badly damaged they need to be replaced anyway. The sludge buildup on neglected engines can mask this problem until it is washed away. So yes, there COULD be a problem on switching over, but your reasoning and personal experience with them is so outdated it is not a fair comparison.

 

ummm, how old do you think i am? dude im only 29.... i went to school just to prove what i know on paper back in 93... im not THAT old, lol. and you only said what i already said like three times now. THE CONDITION of the engine is a big factor... four times now...