mileage difference between 5w30 and 10w30

Status
Not open for further replies.
Joined
Jun 27, 2008
Messages
198
Location
Texas
I've read that going from 5w30 to 10w30 will decrease my mileage.

Anyone know how much we're actually talking about? Would it be noticeable? Normally I get 22 mpg on highway ('02 Envoy SUV with almost 190k miles on her running Penn HM 5w30), would going to 10w30 make me go down to 18 mpg? Or is it more of a decrease along the lines of 21.8.

Seems to me that technically there would be a difference, obviously because it's thicker, but in reality it's hardly noticed by the layman.

Thoughts?
 
The only gas savings would be at start up. When the oils are up to operating temperature they're both a 30 weight oil. I highly doubt you would notice any significant mpg change in the hot summer.
 
Seriously, that's all the "savings" there is? That's like taking "splitting hairs" to a whole new level.


As for summer, seeing as how I live in Houston, where it's summer for all but 2 weeks out of the year anyway, I guess 10w30 here I come.
 
Thats in warm conditions. Get up here when its starts getting cold, thats where the 5w, 0w oils really come into play and offering advantages and that comes down to the base oils and viscosity improvers.

Now if your were talking about jumping from a 5w-20 to a 5w-40, there could be some mpg differences because your jumping to a thicker oil weight.
 
Last edited:
For fuel economy it's mostly about the HTHS. There are some 5w30's with a higher HTHS than some 10w30's. If you get a thinnish 10w30 I highly doubt you'd see any mpg difference, but all you'd theoretically really be gaining by doing so is better shear resistance at the expense of cold start flow.

What 5w30 have you been running?
 
Why run a 10w30? There really is not much benefit even in high temps. I would stick to a good 5w30 like the one you are using or pay a few extra bucks for 'syn' like PP,PU,M1,Edge etc...




10w30 is really kind of obsolete unless you drive a diesel or need an SL high zddp oil for protection.
 
Going to 10w30 since have leak in front gasket, so was told will help with slowing down amount of oil loss. I already use HM oil, so was thinking this will help even more being both HM and a slightly thicker weight.
 
Originally Posted By: chubbs1
Why run a 10w30? There really is not much benefit even in high temps. I would stick to a good 5w30 like the one you are using or pay a few extra bucks for 'syn' like PP,PU,M1,Edge etc...




10w30 is really kind of obsolete unless you drive a diesel or need an SL high zddp oil for protection.


+1 from what has been posted here many 30's are going to shear to 20 WT relatively soon.

If you are concerned about the leak why not Pen HM?? Or longer OCI with M1 HM?
 
Originally Posted By: chubbs1

10w30 is really kind of obsolete unless you drive a diesel or need an SL high zddp oil for protection.


Dont forget OPE!
 
Originally Posted By: AnarchyX
Going to 10w30 since have leak in front gasket, so was told will help with slowing down amount of oil loss. I already use HM oil, so was thinking this will help even more being both HM and a slightly thicker weight.


I dont see how thats going to slow down a leak alone.
 
At operating temperatures, many 10W-30s are thinner than their 5W-30 counterparts when comparing the same label oil.
It really depends upon how the car is used.
If the car is mostly short-tripped in any weather, fuel economy might suffer with a 10W-30 as compared to a 5W-30, but probably not enough that you'd even see the difference, especially in warm weather.
If you normally drive the car a decent distance on most starts from cold, there won't be any difference at all.
You wouldn't see a drop like the one you ask about in your OP if you decided to try 15W-50.
Why not just try Maxlife 10W-30 and see what it does for your minor leak?
I can tell you that Maxlife (10W-40) has really been effective in reducing both oil leaks and consumption with my old BMW.
If that isn't enough, try Maxlife 10W-40.
You won't see much loss in fuel economy, and you live in an area that doesn't see real cold.
 
Originally Posted By: volk06
Originally Posted By: AnarchyX
Going to 10w30 since have leak in front gasket, so was told will help with slowing down amount of oil loss. I already use HM oil, so was thinking this will help even more being both HM and a slightly thicker weight.


I dont see how thats going to slow down a leak alone.


I faced this very question today. I debated between 5w-30 and 10w-30 for the OC on my new-to-me 2000 Saturn SL1. Had it done at a local shop, since I got an unreal deal with a discount and a coupon: Quaker State HM---the older one, not Defy---for $12.67.

Went with the 5w-30 since I don't know if there is a 'real' leak or if it's just the usual Saturn thing. When I picked up the car on Tuesday the oil was low a hair more than half a quart. I plan to check it at least weekly to see how it goes. If it burns more than a quart by 1,500 or 2k miles I plan to dump this fill early and go with 10w-30.

The car has 91k miles on it, btw. My mechanic gave it a thumbs-up on inspection, apart from an emissions leak. He welded on a flex-pipe today to take car of that. We shall see....

I am a newbie oil wonk by this forum's standards, but I tend to agree that changing from 5 to 10 will not solve a serious leak issue. Good luck.
 
Originally Posted By: AnarchyX
Seriously, that's all the "savings" there is? That's like taking "splitting hairs" to a whole new level.


As for summer, seeing as how I live in Houston, where it's summer for all but 2 weeks out of the year anyway, I guess 10w30 here I come.



Your reasoning is good.
The odd thing is that some 10-30s are thinner than some 5-30s. No big differences, but can go either way.
I'd go with a 5-30 because they are modern and very good.
Get a SN 10-30 if you choose to do that.
 
just asking...

does no one read any more?

Originally Posted By: AnarchyX
running Penn HM 5w30


Originally Posted By: KCJeep
What 5w30 have you been running?


Originally Posted By: AnarchyX
I already use HM oil


Originally Posted By: BISCUT
why not Pen HM?? Or longer OCI with M1 HM?
 
I'm thinking about using 10w30 PP instead of the 5w30 PP I'm currently using because of the Noack, 4.7% is impressive and in theory with the same add pack it should reduce intake valve deposit on a DI engine (IS250) and the amount I need to top off in a 10K OCI. Since wife is driving 70 miles a day round trip to work, it shouldn't impact mileage much.
 
Status
Not open for further replies.
Back
Top