5w/20 vs. 5W/30 MPG?

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Okay,
Perhaps I missed it in the 5W/20 Myths thread, but just how much MPG gain does 5W/20 offer over 5W/30? I used about a quart and a half of oil over a 3000 mile period in my 2005 Dodge Grand Caravan (3.8 V6). I use Havoline 5W/20. I was thinking of switching to Havoline 5W/30 on next OC to see if that didn't improve things. Curious how it will affect MPG.
 
In the summer, not much. Try it and calculate your mileage and see first hand what happens. That's fairly decent oil consumption. Does your 05 spec 5w-20? You could even try a 10w-30 after a run of 5w-30 and see what happens as well.
 
The O5 does specifiy 5W/20 motor oil. On a website featuring Dodge owner complaints, it was stated that Dodge claims 1 qt/1000 miles is not excessive. When I had my dealer check it out, his statement was that Dodge does not consider 1qt/300 miles to be excessive. Is he kidding or what!? That's 10 qts between oil changes. That's the equivilant of doing an oil change every one thousand miles.
Let's see Dodge market their vehicles that way "We recommend changing your oil every one thosand miles" and see how many vehicles they sell.
Next OC will be with Havoline 5W/30.
 
At that rate of consumption you'll just need a filter change every 5000 miles and just top ups in between.
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I'd definately give a heavy oil a try, what you got to lose at this point?
 
Whoa I would be throwing a fit with a Consumption issue like that. Hvae your rings seated yet. My Dodge 4.7L used a quart every 2,000 miles then the rings sealed and it just stopped.
 
quote:

Originally posted by otis24:
but just how much MPG gain does 5W/20 offer over 5W/30?

IMHO, outside of a laboratory you won't see a meaningful difference. Too many other variables in the real world like temperature, terrain, wind, traffic, etc.
 
Mostly driving habits, if you at all get on the throttle, and that means anything other than old lady acceleration, you won't see much difference. I saw no change when I switched to 5W-40 from 5W-30.
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quote:

but just how much MPG gain does 5W/20 offer over 5W/30?

To display the API energy conserving starburst emblem on a bottle of motor oil, the formulation must pass the Sequence VIB fuel economy test.

All viscosity grades are tested against a PAO 5W-30 reference oil.

5W-20's must beat the reference oil by 1.7% to 2.0%.

5W-30's must beat the reference oil by 1.3 to 1.6%.

So a good answer to your question is 1% or less.
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I got a new filter and oil today. I am changing even though I only have 3k on the oil. The local supply chain was out of all Havoline except 5W/20. I had beem contemplating trying TropArtic so I picked up 5 qts. TA 5W/30. I will run it and see how it does. If 5W/30 improves things, I may switch back to Havoline in the 5W/30 wt.
I did not mention that the last 1000 miles of travelling was done pulling a camper in the Colorado mountains. Prior to that, I had noticed that I had used about a half quart in 1300 miles. It would seem there is some sort of oil consumption problem.
 
I'm running 5w20 chevron in my 05 grand caravan 3.3, I averaged 25-26 MPG on a recent 1,000 mile road trip with speeds up to 80 MPH, I haven't tried any 5w-30 yet, mine has 5w-20 on the cap and in the manual so I figured go with it.
 
I think your piston rings have not seated yet. I would find me an open road and do some heavy accelerating runs of 10 seconds each followed by a 5 minute cool down between runs. Repeat this for a dozen times and I'll bet your oil consumption corrects itself.
 
Mine specs 5W/20 also, but since there seems to be a consumption problem, thought I would try something different and see if it helps. If not, I'll switch back to Havoline 5W/20 (since I have about three cases stocked up).
 
There's plenty of people on this board who know science and math. I am not one of them.
In my real-world highway driving experience in the past 3 weeks, I've seen my 2001 Civic go from 315 miles on a completely full tank (all highway) to nearly 350. I've switched from Amsoil 0w30 to M1 0w20 and recently also installed new plugs.
I honestly thought my gas gauge was failing and still haven't trusted it all the way down.....but when I fill up, the mileage corresponds with the amount the tank will take.
Very unscientific I know, but I can only report on what my personal experience is proving.
Call it what you will. I call it more money I can spend on overpriced synthetics......we all know they're better anyways, right?
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quote:

Originally posted by jmacmaster:
The figures I've been reading are at .5 to .6 of a mpg. So you won't get any difference that you can measure.

Small change for one car/person... for someone that doesnt measure and log every tank exactly to two decimal places it may not make any difference...

that said, take .5 or .6 mpg improvement... OK, say 0.25 MPG improvement... over MILLIONS of cars sold each year, and what do you get? Over many years of these cars showing up and less efficienct cars being removed - a non-trivial reduction in fuel consumption.

JMH
 
The figures I've been reading are at .5 to .6 of a mpg. So you won't get any difference that you can measure.

I consider a qt. of oil use every 1,000 miles to be excessive, especially in a newer vehicle. Of course the stealerships will tell you that a qt. of oil use every 300 or 1,000 mi. is not excessive on a late model vehicle. Do you think that they're going to admit that your almost new vehicle is an oil-burner?
 
I ran some 5w20 in my mpg test mule a year ago and found no improvement over 5w30 at all and much higher consumption on an engine that normally uses 0 between changes.

I normally run Havoline 5w30 and ran havoline for the 5w20 for my little test. Actually I normally get the best mileage with dino oil and regular plugs.
 
I am now faced with an intresting dilemma: If my vehicle does well with TropArtic 5W/30, is it because of switching brands or switching oil wt.?
Do I stick with TropArtic or switch back to Havoline in 5W/30 wt.
I am guessing both are good oils. TropArtic is cheaper.
Does Havoline offer any advantages over TropArtic? What I think I garned from looking at VOA's was that Havoline had a very high moly count. TropArtic's moly count seemed much lower. How important is moly in the grand scheme of things.
 
quote:

Originally posted by JHZR2:

quote:

Originally posted by jmacmaster:
The figures I've been reading are at .5 to .6 of a mpg. So you won't get any difference that you can measure.

Small change for one car/person... for someone that doesnt measure and log every tank exactly to two decimal places it may not make any difference...

that said, take .5 or .6 mpg improvement... OK, say 0.25 MPG improvement... over MILLIONS of cars sold each year, and what do you get? Over many years of these cars showing up and less efficienct cars being removed - a non-trivial reduction in fuel consumption.

JMH


And think of the fuel savings when all these motors speced 5w20 quit running.
 
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