MPG vs. 40 weight oil

[ChileanSeaBass]

2002 Hyundai Accent GL, Auto, 110K

I'm currently about 2K miles into a 5K OCI with Pennzoil Platinum 10w30 and Bosch D+ filter (it was free). Previously I had been running QSDefy 5w30 with Wix filters. Since the switch I've noticed more engine noise. The Accent has a noisy engine anyways, but it seems to be even louder now than before.

Two other Accent owners have suggested switching to 10w40 saying that quieted their engine. I'm considering this, but don't want to effect the MPG. I currently get 28-30 MPG, and let's face it, that's the only point in keeping this car.

So, should I go with a 40 weight oil and sacrifice gas mileage or deal with the noise and stick with 30 weight? The owners manual says either is acceptable.

 

[SuperDave456]

I'd go back to the DEFY.

It's good stuff.

Why did you go from DEFY to PP?

Also, did you change filter brands/models? I find that the most variation in engine noise isn't caused by oils. It's caused by the filter brand/model.

 

[HerrStig]

Rotella T6 in 5W 40. I switched two Toyota products to it from the "factory" spec of 5-30 and don't notice any change in MPG. The almost 300K engine in one of them is now quieter, and the little start up puff after sitting for a day or two is gone. Walmart has it.

 

[BrianWC]

I'd never really noticed much of a change in mpg when switching grades but maybe I'd never paid close enough attention. On my Civic, I threw in some Supertech High Mileage 10w40 last oci (don't ask) and lost almost 2 mpg easy. I went from being able to beat on it and get 32 easy to barely 30. Guess I'll have to dilute the stash oil...

 

[GumbyJarvis]

No Noticeable loss or gain really,
Ive run 0w20, 5w20, 5w30, 10w30 in my truck, Synthetic, Dino, HM, HDEO the list goes on, and had no real noticeable differences in performance or MPG

Next OC will probably be Rotella T6 5w40 or Rotella T5 10w30.

 

[Lead Shoes]

I've ran everything from 5w20 to 15w40 in my Honda/Acura vehicles I've owned, the only mpg loss I saw was on short trips in town otherwise it was the same.

 

[ChileanSeaBass]

Originally Posted By: SuperDave456
I'd go back to the DEFY.

It's good stuff.

Why did you go from DEFY to PP?

Also, did you change filter brands/models? I find that the most variation in engine noise isn't caused by oils. It's caused by the filter brand/model.


I changed filters (from Wix to Bosch D+), because I got the D+ for free from a friend. In the future I'll be using the Hyundai filters, as I bought a bunch on ebay.

I switched from Defy to PP at the suggestion of a few folks that it may help clean the engine up. It was the same price, so no big loss.

 

[Rand]

probably notice abit of mpg loss if you do alot of short tripping.
Esp if getting abit colder now(vs summer)

that being said 10w40 was listed as acceptable for that engine
in the manual.

so do whatever you wish.

 

[ChileanSeaBass]

My daily commute to work is 40 miles round trip, half on the interstate and half city driving. Every Sunday I do 60 miles round trip almost all on interstate, and maybe 5-6 short in-town trips per week.

 

[bourne]

Try some maxlife or maxlife next-gen goodness in 5-30/10-30 flavour. You might just be surprised by it if you haven't tried it yet .

 

[Mitch Alsup]

Originally Posted By: ChileanSeaBass
I currently get 28-30 MPG,


A switch to xxW-40 oil might hurt you at the 2% level (or about 0.6 MPG) do you think that you would even notice--that is are you taking enough careful notes on MPG to even see this level of change?

 

[ARCOgraphite]

Originally Posted By: ChileanSeaBass
...
I switched from Defy to PP at the suggestion of a few folks that it may help clean the engine up. ...
I was at a fancy bar one night, and some sorta strange dude suggested I migh try PP, but I declined as I didnt want to switch teams at this juncture ... ... . Ahem ... .

 

[bepperb]

I'd be more worried about starting the car this winter than mileage of you go to a 10w-40 oil. Not sure if you park on the street and what hours you work but there's always one or two sub zero starts where I'll take whatever help I can get.

 

[ChileanSeaBass]

Originally Posted By: bepperb
I'd be more worried about starting the car this winter than mileage of you go to a 10w-40 oil. Not sure if you park on the street and what hours you work but there's always one or two sub zero starts where I'll take whatever help I can get.


Here in NC, the coldest it gets in the mornings is around 15-20, and that's rare. I don't think I've ever had a sub zero start in the 15 years I've been here.

 

[bigjl]

My wife had a 1996 Accent with the 1.3 engine and autobox.

It used to use a bit of oil and had a tiny sump.

About 3.5 litres if memory serves.

The wife used to run it low on oil all.the time. Running for days on end with the oil.light on. She used to put a pen on clocks so she wouldn't see it!

I used whatever 10w40 was cheapest in it. OCI around 10k. But is used to use some. So no biggie.

The car was sold 3.5 yrs ago, rather given away, and is still.running today. Tough little car. Engine was pretty harsh though.

As far as visc affecting economy. I sold a Mondeo tdci that I had run on 5w30 Magnatec or 5w30 Ford Semi Synthetic for three years. Mate had alternator done and asked for an oil.change.

Don't know what he put in but he reported a 3/4 mpg drop in economy.

Couple of months later I changed it again for him. Using Castrol Magnatec 5w30 ( B1/B5) and the fuel economy went back to normal.

I can only assume the garage put a standard B3/B4 5w30 or worse some bulk 10w40.

That car still.uses no oil. And does all highway use. Off peak. Lots of quiet roads in 15/18oC temps and is running a 10k OCI

 

[chubbs1]

I would almost bet you my last dollar it is the non-OEM filter. The Bosch D+ especially. I love the filter but it does not mix well with the Hyundai engines. Try the OEM filter and switching back to QS Defy 5w30.

Why go to a 40grade if the 5w30 was OK?

Go OEM oil filter, the Sonata I have is extremely picky with filters. M1's and K&N work OK, but I can tell a real difference with the OEM.

 

[ChileanSeaBass]

Originally Posted By: chubbs1
I would almost bet you my last dollar it is the non-OEM filter. The Bosch D+ especially. I love the filter but it does not mix well with the Hyundai engines. Try the OEM filter and switching back to QS Defy 5w30.

Why go to a 40grade if the 5w30 was OK?

Go OEM oil filter, the Sonata I have is extremely picky with filters. M1's and K&N work OK, but I can tell a real difference with the OEM.


Running 5w30 it was noisy as well, but again, that was with a non-OEM filter. I'll give the 5w30 a whirl with the Hyundai filter and see if it's any better. If not, then I'll look into the 10w-40.

 

[Snacks]

There was no statistical difference in 5w20 and 0w40 for me. My data below:


2006 Ford Focus 2.0 Duratec w/140k
M1 & NAPA gold
25 fill ups each at same pump
Same route each day (I only drive this car to work)
Checked tires 1/week
97% hwy - 3,250 avg RPM - 98.5 miles each way (197/day)

MPG 5w20
avg - 28.5 (27.2-29.6)

MPG 0w40
avg - 28.3 (26.8-29.9)

I think there is more variability in gas/weather/driving than in 5w20 and 0w40.

 

[mechtech2]

Try anybody's 5-30.

 

[fdcg27]

I've used 10W-40 in both of my Accords and didn't see any drop in fuel economy from 5w30.
28-30 mpg is all you get out of that little thing?
Both our Accords will do better than that, as does my BMW.
Anyway, 10W-40 will likely result in quieter and smoother operation and shouldn't hurt fuel economy much if at all.
Only way to find out is to try it.
Maxlife Nextgen would be a good pick, but so would Pennzoil conventional.