Synthetic Oil interval?

[kurisu]

Hi guys,

I decided to go synthetic oil this time. I picked up valvoline sythetic blend 5w-20 with mobil 1 filter at my local autozone for $21.99. I've been doing 5k oil change. I'm not sure if the interval for synthetic oil is more than 5k. :smile:

[R2D2]

Valvoline Syn blend I'd go 5k/6 months. Unless you have a nearly 100% highway driving cycle I'd go no further with that oil without a used oil analysis that included TBN. If your still under warranty I'd stick to 5k regardless.

R2

[malibuguy]

when ever i used synthetic in cars, i automatically go to 5k...but it figures, thats what toyota specifies for the regular oil change interval

i run mobil-1 0-20w Eco oil

[ecc_33]

after my oil analysis i wouldn't use 5w20. Don't know if its blow by from rings or what but my oil had a lot of gas in it causing the oil to thin out some

[bankrobber]

I would go at least 7,500 with a good wix filter. I went over last oil change and went to 11,000 miles and oil still at full mark looked ok too. Running Mobil1

[fnkngrv]

are you running NA or FI?

[bankrobber]

not sure what that is

[mazilla]

I go 3k, but I get the 19.99 Mobil 1 gallon jug from Walmart and a cheapo fram filter so it's the same price as a regular dino oil change.

[fnkngrv]

not sure what that is


NA = Naturally Aspired, in this case stock
FI = Forced Induction, boosted with either a supercharger or turbo

[bankrobber]

NA = Naturally Aspired, in this case stock
FI = Forced Induction, boosted with either a supercharger or turbo


lol, mine is stock...NA

[R2D2]

after my oil analysis i wouldn't use 5w20. Don't know if its blow by from rings or what but my oil had a lot of gas in it causing the oil to thin out some

I'm afraid that's pretty typical, regardless of oil weight used. It's a big part of the reason I'm not a fan of blindly extending oil change intervals regardless of the oil type, or weight used.

Although it seems odd thinner oil isn't necessarily "bad" where fuel is present and other factors about a chosen oil can be much more important than it's rated viscosity.

My last report was about 1.6% fuel dilution.

R2

[swidd]

Does it matter if there's some fuel circulating in the oil?

[Happy Little Pony]

Does it matter if there's some fuel circulating in the oil?


Even in a modern, fuel injected car there's always going to be some small amount of unburned fuel that makes it into the oil. Most all of this evaporates on a long drive when the engine gets up to full operating temperature for an extended period. But if a person rarely (or never) drives their car long enough for the oil to get really hot, then this fuel (as well as other contaminants) never gets burned off. The oil just gets more and more diluted by contaminants.

This explains how one car can go 10,000 miles and its oil is still good, but another can go 2,000 in the same time and its oil is bad.

[Hershey]

Still need to stay with the 5,000 mile or 6 month interval to keep your warranty . Doesn't matter if it's conventional , a blend or full synthetic . Also keep your receipts of the oil and filter for records in case there's an issue .

[R2D2]

Even in a modern, fuel injected car there's always going to be some small amount of unburned fuel that makes it into the oil. Most all of this evaporates on a long drive when the engine gets up to full operating temperature for an extended period. But if a person rarely (or never) drives their car long enough for the oil to get really hot, then this fuel (as well as other contaminants) never gets burned off. The oil just gets more and more diluted by contaminants.

This explains how one car can go 10,000 miles and its oil is still good, but another can go 2,000 in the same time and its oil is bad.

Well put.

If the fuel doesn't get evaporated out it can thin oil out, affect lubrication and create deposits.

[jambo101]

I go 3k, but I get the 19.99 Mobil 1 gallon jug from Walmart and a cheapo fram filter so it's the same price as a regular dino oil change.

Whats the logic in changing the oil at half the mileage the manufacturer recommends then cheaping out on the filter?:confused: