Synthetic Oil Questions

[1999silverado1500z71]

Hey everyone, I have a 1999 Silverado 1500 with a 5.3L. Lately I have been debating about switching to synthetic oil. I have had the truck for just over 3 years and have pretty much always used Valvoline Premium Conventional 5w-30 oil and a Fram filter and I change oil and filter every 3,000-3,500 miles. The truck sits outside now that I'm at college this year and its starting to get cold here in Iowa and I go to work at 5:00 in the morning three times a week. The drive to work is 2.5 miles of city driving under 45 mph with about four stop lights. So the engine only gets half way warmed up and never reaches normal operating temperature. I am wondering if it is worth it to switch to syntheic oil. If I decide to switch I think I might go with Mobil 1. I see a lot of people say good things about Mobil 1 on here. But there are a few additional questions:

 

Will I encounter any problems switching from Conventional Oil to Synthetic Oil?

AND Would it be safe switching from Synthetic back to Conventional?

 

Would switching to Synthetic Oil even be beneficial on account that the truck will be sitting outside this winter and that the engine doesn't warm all the way up due to my 2.5 mile drive to work three mornings a week? (I do let it warm up for about 2-3 minutes before I take off from my parking spot.) (I'm in Iowa and every winter it seems we have a period were temps get below zero for a little while but besides that its not terrible.)

 

Or should I just stick with what I'm using now? (Valvoline Premium Conventional 5w-30 changed every 3,000-3,500 miles)

 

 

Will I see any fuel mileage gains from switching to Synthetic Oil?

 

 

I would apreciate any other information I should be aware of that I have not mentioned. (The truck does hardley any pulling/towing if that needs to be taken into consideration. Just mostly highway and short distance driving.)

 

Thanks, Nick.

[rodram]

here's my two cents worth...

- you can switch to synthetic with NO problems and you can switch back to conventional again any time with NO problems

- you will not likely see any performance difference between the oils, for the use you describe

- your short distance commute winter driving (very similar to mine, except we already had 0 F here this morning) is what will cause deterioration of your oil life... your engine will build up condensation as it rarely gets a chance to fully warm up... this moisture ends up in your oil crankcase, so it would still not be advisable to try to justify extended life or extended miles if your had synthetic oil... synthetic or conventional with this type of winter driving you should not leave the oil for more than 6 months, even with only less than a few thousand miles on it.

- synthetic will flow a little easier when cold so you get better instant lubrication on cold starts

 

... some people don't like FRAM filters (something to do with how the internals are assembled)... most people say that ACDelco, WIX, and Napa are the best for our trucks.

 

So it comes down to your choice, synthetic is great oil and will be a little more expensive (depending on how you buy it)... but I don't think your truck will suffer any hardship with you sticking with conventional oil with the regular filter & oil changes that you maintain.

[ColoradoSkiCountry]

I would just stick with what your using. 5W30 is just fine for what your doing though I'd defensively go with an AC/DELCO or NAPA oil filter and stop the Fram crap. Being in school your on a budget. No need to blow off extra $$$ on synthetic when conventional will do just fine and likely get you to the point later on down the road where you get another truck.

[Black02Silverado]

I would stick with what you are doing now. As stated above, your engine never gets warmed up so condensation builds up inside the engine. Also your engine is running in Closed loop longer which means it is running rich longer and that will also allow fuel to get down and into the oil. Those two factors are hard on oil. Staying with the oil change interval you do now and the oil you are using will serve you well.

 

Synthetic would protect the engine better in these conditions but not worth the money since you are changing it every 3k. As for cold flow Valvoline is just fine. Conventional oils have come a long way in cold flow properties over the past ten years.

 

As for Fram oil filters, they have a bad following due to issues caused by others using them. But I have seen many engines go past 300k when a Fram oil filter was used.

[mxdirtrider56]

Just stick with what your are using now. No need in spending the extra money on synthetic. Just wake up a few minutes earlier and let your truck run a little bit longer before you leave. In the middle of winter I let my truck run longer than you do to give a chance to get good and warmed up before I leave. Conventional oil will be fine. Use a delco filter.

[bluegmctruck]

With your truck being a 1999 (assuming high mileage) i would stick with conventional oil. The reason is that conventional oil can leave behind slug that can clog cracks in your engine and when you switch to synthetic it will clean out the slug unclogging the crack which can cause a leak. i know a few people this has happened to. Conventional oil works just fine especially if you change it every 3000-3500 miles.

[big_dawg74]

Nick, I agree w/ previous posters. Don't spend extra $$ on synthetic. Valvoline conventional is a good oil. I am curious as to what your annual mileage is. Five or six miles a day does not add up very fast. How long does it take you to get to 3K miles? At a minimum, I would look at changing your oil twice a year, (maybe spring and fall?) regardless of mileage. And yeah, a Wix, AC/Delco, Purolator, etc. filter will be better than the Fram.

[whitelion]

Seeing as im the new guy on the forum i will humbly assert my opinion. Im more or less in the same situation with my truck at school in that it lives out side in the cold, and i don't drive it alot of miles a day except when i drive home which is 600 miles round trip. however I still made the switch to Mobil 1 partly cause my grandfather swore by it and his '96 silverado lasted him over 187,000 miles with 0 engine issues (he only got rid of it cause he just wanted a new truck after he'd had that one for like 15 years). What i learned when i did my research was what the difference actually is and that syth is simply a more pure oil, and the molecules are more uniform than mineral base so that on a high-mileage engine the engine wears less because the lube is more even (frankly im not even sure i buy into it) but the kicker was that i did the entire oil change with a fram filter for around $26. I couldn't have saved more than a few dollars anyway. To me it seemed to be worth it. Obviously its your truck and your money so do what is best for you, but i hope my experience helps a bit. Im a few hundred miles short of 3000 but ill be due for a change when i get back home for thanksgiving and ill see how dark the oil is than. remember this too. the single most important thing you can do for your engine to keep it running well for a long time is change your oil regularly. don't skimp you really cant over change it. as for cracks in your engine block being blocked by sludge, ill be the first guy to admit i don't know it all, in fact i don't even know alot but if your engine block has cracks which oil can leak through, i think you got bigger issues than deciding between syth and mineral base.