From 10W40 to 0W30

[i-DSi]

Hi all,
Changed the oil of my wife's car (little, French Renault Twingo 1.2 '08). There was 10W40 on it and I shifted to fuelsaving 0W30 (allowed according to manufacturer).
The result should be noticable as this car is:
- always parked outside (so cold)
- driven for approx. 2 to 3 miles/drivecycle
Anybody did a comparable change and noticed any difference?
I will keep you posted if I see any difference, but this will take maybe two months (wife doesn't drive often and as I drove this car today for a long trip the fuel consumption will have dropped for this tank).

[theholycow]

Which brand of 0W30 did you use?

[i-DSi]

Originally Posted by theholycow

Which brand of 0W30 did you use?

The original Honda branded oil, same as for e.g. Civic Type R.

[bobc455]

I've found that there is a small difference between oil viscosities, however I usually drive older cars and sometimes I'll hear/notice a difference when I use a light oil.

-Bob C.

[theholycow]

I didn't know that there is Honda-branded oil, but I guess that makes sense...I think most major manufacturers sell their own brand of oil too. How does the price compare to major independent oil brands? In the US I would expect to pay significantly more, but I don't know if the same price issues exist elsewhere.

I used this 0W30 in my VW:

(Castrol Syntec European Formula 0W30)

[i-DSi]

Oh yes there is Honda branded oil with a Honda partnumber, I think also in the States, but not all manufacturers sell own branded oil. The Honda one is from a Japanese manufacturer. Forgot the (difficult) name.
To be honest, I didn't compare prices as I could get this oil very cheap. But you're right: normal price at dealership is 76 euro for 4 1-liter bottles (= very expensive).
In my previous Honda motorcycle I also used Castrol.
For my current MCycle I use the original branded Honda motorcycle oil (10W30) for same reasons as the 0W30 (reduction).

[Jay2TheRescue]

I think everything I own can be classified as an "older vehicle". I use 0w30 in my 98 GMC, but I use 5w30 in my 81 Buick, and 10w30 in my 86 Chevy. The engine in the 86 Chevy just isn't in that good of shape anymore, and a slightly thicker oil probably does it some good. I'll probably switch the Buick to 0w30 on the next oil change, haven't yet decided for sure though.

[i-DSi]

Originally Posted by Jay2TheRescue

I think everything I own can be classified as an "older vehicle". I use 0w30 in my 98 GMC, but I use 5w30 in my 81 Buick, and 10w30 in my 86 Chevy. The engine in the 86 Chevy just isn't in that good of shape anymore, and a slightly thicker oil probably does it some good. I'll probably switch the Buick to 0w30 on the next oil change, haven't yet decided for sure though.

Hi Jay,
A problem when using 0W30 when it's not allowed by manufacturer can be the flow of the oil pump. You should be sure it can still give enough pressure on low revs with the thin oil.
If this is fine, then thinner oil is always better for lubrication than a thicker oil.
If you lose oilpressure somewhere in the oilpath because of thinner oil, than your engine is really worn out.
With thinner oil you can have a bit more oilconsumption, but at least there is oil between the metal parts. With thicker oil it will take longer before there's lubrication on the most far away points.
Also interesting: switching from 5W30 to 0W30 changes nothing when your oil is hot. It can only be good for your engine.

[Jay2TheRescue]

Exactly. My 86 Chevy already comsumes a lot of oil through various drips here and there. I didn't want to make it worse with a thinner oil.

[theholycow]

My understanding was the opposite, that thicker oil is more difficult to pump but in a worn engine with larger clearances the thicker oil would be better lubrication...while thinner oil is easier to pump everywhere quicker, and gets into tighter clearances better.