2 different Quicksilver oils
 

Hey, ready to change the oil in my 96 Formula 303 with 502 mpi's. I want to put in Mercruiser Quicksilver 25W 40, but I see there is a regular and a synthetic blend. The synthetic blend is rated FC-W. Is there any advantage to using one or the other? I'm in SW Florida, so, boating season is still on and typically 70-80 degrees this time of year. The water temp is usually in the 60's & 70's now (not to rub it in with the northern readers, but just to know what the conditions that the boat is operating in).

i use the regular in most applications,i don,t really think syn blend is worth the money.for me full synthetic or regular.

Dino oil is still good to use, in my engines I use synthetic Mobil one 15W-50. Last time I got it was at Walmart for around $23.00 for a jug. Drives, Merc High Performance. A lot of god oils out there.

FWIW circa '96 7.4lx mpi's here with no leaks until I ran Valvoline VR1, now both leak. VR1 is full synthetic, should've kept with non-syn and added zinc as I had previously done.

yep,i have seen several high mileage engines develope oil leaks after switching to full synthetic.

Same engine (but 2000) . Used the regular 25/40 for the first year or two and then when the synth blend came available switched over to it. Considering going to the full synthetic 20/50 as at the Merc dealer there's not a whole lot of difference in the price between them . (believe it or not)
Without getting into the entire controversial oil argument they're all very good and you won't have any problem.

Never seen a motor damaged from any oil, only lack of maintenance

Being in FL I would just use straight weight no W needed.

I use Dino straight 40 in the 454, and Brad Penn straight 50 in the 509

VR1 is available in conventional ,is a fantastic oil, and comes with plenty of zinc/phosphorus and foam control agents (think higher reving hyd flat tappet and hyd roller) lifters :)

Grey bottle is conventional...black bottle synthetic....was up thru this spring anyway.

Driven racing oils. They also put out by far the most education about oils and it is not sales pitches about their own oils. IMO they do a really good job on both ends of the coin. Oil products and educating the end users.

I think this time I'll just use the regular Merc stuff through the winter. Then, I'll reconsider changing in May when I change the oil again. Thanks for all the replies!

FC-W is the NMMA rating for 4-cycle water cooled marine engines.

Why both oils are not NMMA FC-W rated I don't know. But a lot of people, myself included do not use a NMMA FC-W rated product or even a NMMA rated product.

Personally I been using synthetic oil in all my vehicles and boats forever. Just can't go wrong with synthetic! Not sure if the FW has an advantage in salt water areas or not?

An Amazon Prime deal today,
$25 for 5 quart jug conventional VR1 20W-50 :rock

Today Only Prime Deal. 3 Pack 5 quart jugs Valvoline VR1 20w-50 conventional:
Reduces to $52.87 when added to cart. :thumbs

It stays $66.09 in my cart...what gives? Never mind you have to actually start checkout not just put it in your cart....Nice deal!

I had the graphic. Can't find it now, but the synthetic blend is the #1 to buy, #2 would be the 'regular' 25w40.

The price difference seems low enough they should just drop the 'regular' one.

Thanks for the correction. I moved it so fast to purchase I didn't notice that part. :)