severe service condtions oil change

[Racincc85]

I've got a 99 nissan altima with 120k on it. I currently am using mobil 1 extended performance fully synthetic 5w-30 oil in it. It says on the bottle that the oil has a life of 15,000 miles and that this is a safe interval provided that you do not drive numerous shoft trips where the oil doesn't get hot. I usually change it at 10,000 just for peace of mind. The oil always comes out it decent condition so I've been keeping this interval.

I am a college student that doesn't have time to work many hours during the week and I can't have a job where the schedule is changing all the time, so I might be taking a job delivering newspapers because it fits my schedule perfectly. I'd be using my own car to deliver them. I'd be doing it really early in the morning so there wouldn't be many if any other cars out, so I wouldn't have to do any stopping. I could drive at 10 mph and just throw the papers out the window. Now here's the meat of this long winded question: Should I modifly my oil change interval?

I know that if the car meets the conditions defined in the manual for severe service then yes, but mine situation is kind of hazy. I;d be driving 20 mins to get to the location where I would start to deliver, then I would be coasting around for probably 2 hours or so (I'm only going to be delivering one morning per week) I was going to just coast in 1st gear to keep the revs up so the engine is above idle for better oil pressure. I would think the oil would stay plently hot doing this, and I wouldn't be changing speeds alot. The fact that I'm using synthetic oil makes me feel better, but I thought I'd ask for sure.


Also, what are your opinions on the mobil one extended performance oil?

[TheSilentChamber]

Doing what your doing now will work fine.

[MagicRat]

^^I tend to agree.

You may be over analysing this. Strictly speaking, you are not doing short trips. As you say, the oil will heat up and stay hot, so you reduce the oil contamination effect of the blow - by gases, (those partially-burned hydrocarbons that leak past the piston rings. ) This would reduce the need for a more frequent oil change.

However, if you determine the oil change interval by mileage alone, you are underestimating the need for a change. Your engine will be functioning for a much longer time to accumulate the 10 k miles between changes.

IMO if the majority of the miles are accumulated by these deliveries, you may want to consider increasing the mileage frequency of the oil changes.

[Racincc85]

Thanks for the advice. I usually do tend to overanalyze things and that's exactly where this question came from.

I

[biggbabysweetz1]

ill give you a little insight on oil changes (yes i do work at valvoline)
Regardless of oil type, weight, etc. manufacturers recommend an oil change every 3,000 miles or 3 months HOWEVER having used mobil 1 syn myself for the past 2 years i can say i drive about as much as you say you would be delivering. 10,000 miles is perfect try it like this 10,000 miles or 4-5 months whichever comes first. but to get the most performance and longevity out of your vehicle you chould follow your manufacturers recommendations. VIOC has a nifty tool to help you with other service recommendations if you wish, its free and if you go to ANY valvoline instant oil (not places that just feature valvoline oils) they can pull up a vehicle history including services done by you, and valvoline. visit this little deal here http://www.vioc.com/pages/carhistory/index.asp
if youve never been to a valvoline before you wont have an MVP number
and if you need an MVP send a pm and ill get one from work