5w-20 Or 10w-30 ? - Page 2 - Ford Forums

**360ci** · 05-02-2009, 08:50

Quote:

Originally Posted by mercdriver

Well I finally did it. Went to 5W-20 Full synthetic- Mobile 1. It took 6 quarts total.
Before I went to full I bought a quart of oil flush, ran it for five minutes with a cold engine as stated. I really didnt see any gunk come out but the color of the previous regular oil was darker. this engine has 46 k miles on it , the inside of the oil cap where the rockers etc are looked pretty clean - no gunk at all and probably didnt need the flush. I dont know if it would or should be a good idea to flush before oil changes. I also dont know if I should now change every 5k miles. I used to always change at 2.5 or 3k on my previous marquis since I had lots of idle time smoking in it, I dont smoke in this grand marquis.
thanks for all of your inputs.
art

If the engine had over 120K, I'd flush it, but with 46K, it wasn't necessary to do. As for change interval, read the bottle. If the oil is good for 7.5K, you can change it around 6.5-7K if not keep it in for the whole 7.5K. If the oil is good for 15K, then keep it in for 13-14K. You can go over the change recommendation limit as well, because if you think about it, regular oil requires a change around 3K, but most owners always go over and the engine will still last a good while before major service is required. Not to say that's its OK to go over the change interval of the oil, but occasionally it won't hurt.

When I go down to Florida, I change the oil before I leave and as it's all highway I'll easily put 10K on my 7.5K oil. Around 8K it just STARTS to turn dark brown. Synthetics are the best. In my area, regular oil runs close to $5/quart for Quaker State 5W30. Full Synthetic is double the price and you can drive up to 4-5 times the distance.

mercdriver · 05-02-2009, 18:40

360ci, thanksfor the info, I will have to read the empty quart that I kept. I took all my old oil and trans fluid from about 3 years sitting in the back yard to the hazardous waste site today and filled the large 5qt with old oil also, but I can look up the mileage on the web. I bought the MOBILE1 at walmart for 26.00/5qts and 1qt for about 6.50 here in San Antonio. I will see what SAMS CLUB sells it for, but I probably wont stock up on it if its 5k or more on changing it. again thanks. as for a difference In performance I havent noticed nothing today, I assume its just a better oil for the engine. I yet have to floor it, but trying not to. Most I've done is about 82 in a moderate pace getting on the highway - which didnt seem to be a problem. Down here you dont get much of a break sometimes to get on a highway.

**360ci** · 05-02-2009, 21:10

That's one thing Canada is more known for - long merging ramps onto the highways. It's just a shame that as soon as that dotted white line starts, people feel the urge to merge into 70mph traffic at 30mph...and they have half a mile of road left to get up to speed before having to worry about getting over! Ah well.

On a side note - oil will keep indefinitely. I'm using 6 year old semi-synthetic (Quaker State 4x4 that I had leftover when I owned my gas station and couldn't sell it in time) in my small engines. Oil will only break down if you use it. I would imagine if you kept it for 40 years, it would still lubricate the same, but you might burn more of it than if you used brand new oil.

If you can find a sale on Mobil1 oil, pick it up so you have it for your next oil change. I'm sure you'll come across at least one sale, somewhere, as you pile on at least 5K. It's on sale in my area frequently (every few weeks). I use Amsoil though, 56,000kms (32K) on their top of the line oil in regular service for $12/quart.

Synthetic - 30K
$60 for 5 quarts
$22 for one filter

Regular Oil - 30K
$16 for 5 quarts x 10 changes = $160
$5 for one filter x 10 changes = $50

Cost to drive 30K on synthetic = $82
Cost to drive 30K on reg oil = $210

Savings of $128. Most folks tend to burn less oil in between long interval changes when running synthetic. So factor in $12 for one synthetic quart every 10K = $36. Now factor in one reg oil quart every 3K - $32. Synthetic still wins by $124!

floater3 · 05-06-2009, 16:32

With all the variance in types of driving and extreme weather conditions plus how many miles you drive each year, each vehicle will be different. I would question using any oil for 30,000 miles if you do stop-and-go and/or short trips very much. There's no doubt full synthetics are better but if they get diluted or the extended-use filter isn't up to snuff, will they really protect much better at a comparable cost? 30k is a lot of miles on the same filter...at $22 each I guess they are supposed to be much better? I would make sure of that. Some recommendations are to change just the filter after certain intervals....and that will drive your costs up. I use the Castrol blend and the $ would look like this maybe:

A tweaked comparison table:
---------------------------------------------------
Synthetic - 30K:
$60 for 5 quarts
$44 for two filters (still...it's 15k on a filter)
$25 oil analysis at 15K-20k(?)..to make sure it's actually lasting that long.
= $129

Blend - 30K (changed at 3750 mi. intervals):
$20.50 for 5 quarts x 7 changes = $143.50
$5 for one filter x 7 changes = $35
=$178.50

---------------------------------------------------

Cost to drive 30K on synthetic = $129
Cost to drive 30K on reg oil = $178.50

Now that's only a 28% saving vs. the 61% your initial example showed. Personally, I like to know my engine is getting fresh oil and the wear particles are being removed at just a bit shorter intervals than 30k.

daddylobster · 05-07-2009, 19:32

I live in texas,way up north near dallas. I put 5-20 in my new grand marquis only because it was recomended and I didn't want waranty issues. I gues ford knows what they are talking about. 225k and the oil still looks new not black,changed faithfully at 3k I sell amsoil but never got around to changing to amsoil. Think of the money I could have save with the full syn. I guess the Motorcraft 5-20 is pretty good stuff.

87_Crown_Vic · 05-08-2009, 07:37

with my older cars, i would have to yank engines and seal them up to use synthetic. if i were to use that synthetic that says it can go for a long time, i would have to add oil ... my cars go thru about 1 quart between 4,000 mile oil changes. i prefer Valvoline myself but to each their own

floater3 · 05-08-2009, 09:54

Yeah, I'd heard the synthetics will get past seals easier but only if you switched to it from regular oil? Doesn't seem like it would get past gaskets easier but maybe that,too?

Any of the major brand oils will do as long as you change it regularly, since they all have to meet the same API specs. So what's your opinions on keeping an oil filter in for 30,000 miles? A good idea?