For those who use the cheapest oil you can get,,,

[Bullet]

Just wondering if you would use 10w40 for your engine where it is recommened to use 5w20 or 5w30?

I passed up Havoline 10w40sm at a buck a quart because my cars are fairly new, but now I wished I would have grabbed all the bottles.

 

[oggb]

There's a 50/50 chance. Depends what it was on the shelf next to.

I run 15w-40 in my car that specs 5w-30.

 

[fdcg27]

In warm weather, pretty much what you always have where you are, it would be fine.
I don't think you'd even notice any difference in fuel economy.
I've had 10W-40 in both of the Hondas, and saw no diference in either fuel economy or performance.
Also, Havoline is a pretty thin 40, not much thicker than the heavier 30s.
For a buck a quart, I'd have grabbed all they had.

 

[Mr Nice]

I bought all the Havoline (various weights) that PepBoys near me had on clearance, luckily mostly 5w20, 5w30 and 10w30 but the remaining 10w40 and 20w50 will be mixed with 5w20.

 

[CATERHAM]

A typical dino 10W-40 will decrease your fuel economy anywhere from 4 to 6 percent over a 5W-20 dino.
Consiquently over the length of an OCI what have you actually saved vs buying some 5W-20 on sale not to mention the reduction in power?
Sounds like false economy to me.

 

[jstutz]

Originally Posted By: CATERHAM
A typical dino 10W-40 will decrease your fuel economy anywhere from 4 to 6 percent over a 5W-20 dino.
Consiquently over the length of an OCI what have you actually saved vs buying some 5W-20 on sale not to mention the reduction in power?
Sounds like false economy to me.


4-6% is not a given. Depending on temps and driving conditions it could hardly be noticeable. I would have bought all of it and if i was uncomfortable with it i would mix it with something thinner until i used it up.

 

[fdcg27]

Caterham!
A 4-6% decrease in fuel economy?
I doubt that.
That has not been my observed result using 10W-40 in a 5W-30 application.
.4-.6%, yeah, maybe.
4-6%?
No way, regardless of the greater HTHS value of the 10W-40.
I log fuel used with every fill, so I would have noticed a consistent 4-6% decline.
It simply doesn't happen in actual use.

 

[PandaBear]

I wouldn't, the fuel economy penalty over the interval would have paid for the price difference.

What I'd do however may be to use it as top off oil mid way to reduce the shearing.

 

[Hermann]

I will chime in at 2-3%. If I run 5w-30 in the Tacoma, instead of 20 wt in similar seasons, it will cost me a full MPG over the 12 or 13 tanks per OCI. I have used it 2 times, and have a fill of QS GB 5w-30 to use next OCI, and will bet it happens again .

 

[Cristobal]

I use lighter oils these days, but in the summer of 2008 went to Yellowstone and back on Mobil 1 15W-50 Extended Protection in my car that specifies a 10W-30. There was no decrease in mileage at all as far as I could tell.

 

[Steve S]

There is less than a percent difference in the different viscosities. I had a Facrory engineer from GM talk about the CAFE standards and the oil during one of my continueing educations when working in the Field.

 

[CATERHAM]

The average fuel economy gain or lose between grades is 1.5 to 2 percent. That's based on a 0.6cP HTHS vis change.
On a car that averages 30 mpg, that's 0.5 mpg and if you can measure that amount of change you're a better man than me.

 

[Triple_Se7en]

Originally Posted By: Bullet
Just wondering if you would use 10w40 for your engine where it is recommened to use 5w20 or 5w30?

I passed up Havoline 10w40sm at a buck a quart because my cars are fairly new, but now I wished I would have grabbed all the bottles.


I would have bought all they had and blended it equally with 5W-20.

All conventional oils brands and weights are compatible. My Caravan beater with almost 300K (purchased new in 1994) is living proof you can mix oil brands & weights all you want.

 

[vintageant]

I've kept very detailed MPG records for the Accord since I got it in October 2006. 49,494 miles, 1,879 gallons, 26.3 MPG, $5,309 at average $2.83 gallon (87 octane).
Over the past 6 tankfuls with same QS 5W20 dino, under similar driving conditions, MPG has varied from 23.9 to 26.2. That's 9.6%

So, my point is, can one really accurately measure the difference in MPG when using different oil specs?

 

[ahoier]

I've always been one to go by the books, but I'd probably buy it up, and just spread it out a couple of OCIs, mixing 1 quart or 2 in each OCI along side the 5W-30 or 5W-20.....ehehe.

But I don't know, 10W-40 just seems too thick for a vehicle that specs 5W-20 or -30.....I know everyone goes on about the "oil clearances" and how modern engines "dont want" the heavier weight oils.....

and presumably using the higher weight oil could cause pre-mature engine wear....since it would take longer for the oil to "get to where it's supposed to be" or so they say (but my thought too, would it being "thicker" make it "stay where it's supposed to be" when you shut the engine off? hehehe)....

And then I have this mental image, of a hiker walking through a trail of mud (that would be the 10W-40), and a hiker walking through a trail of tall grass (5W-30....? lol).

Obviously, easier to get through the trail of tall grass, than it would be to trek through a trail of mud

 

[CATERHAM]

Exactly, there are so many variables involved to accurately measure. So take it on faith, you're loosing out enough in fuel economy to not make the use of heavier oil worth it.

Having said that, I can sure notice the increased drag of a 40wt over a 20wt on start-up even at room temperature which is not surprising considering a 40wt is at least 100% heavier at that temp'.

 

[fdcg27]

Fuel economy never varies by that much in any of our cars, except for the change to winter gas and the change beck to summer gas.
Given the way we use our cars, fuel consumption never varies by more than ~1 mpg in any given season.
Best seasons for fuel economy, for us, are spring and fall, since its fairly warm, the gas is summer blend, and it isn't warm enough that A/C is required or even desired.
YMMV, but I find fuel consumption to be very consistent in each season, and we do have all four here.

 

[crinkles]

My Manual says 10w-30, 15w-40 and 20w-50 OK for a Camry 2AZ-FE. According to temperature. I can run a 20w-50 if i wanted, but usually I'd need to get a 15w-40 or lower if I wanted a spec more recent than SG!! Today I saw an SN API 15w-40 (think it was GTX).

 

[hhu168]

I used to use 10w30 and 10w40 on my Ford Taurus. I use 5w30 now. I think my fuel efficiency was better when I used the heavier weight, tune up time...