Raymund

I've been using the recomended 10w30 grade for my car and in the span of 3yrs. I've noticed, within that time, the oil pressure at idle and peak is now at a lower value. The car has 40k miles. The last 2 years, I've been tracking the car once a month. I'm thinking about switching to Mobil1 0w-40 considering it should provide better protection at both end of the spectrum compared to their 10w-30. The oil gets up to 250F at the track and I notice a drop in peak pressure at that temp. Will that extra bump in viscosity be of any help during racing? Since it's rated at 0w-40, I would think it would be adequate for daily driving as well? Anyone who has used an out of spec oil grade care to share the results be it good, bad, or detrimental?

PhucNguyen57

That is what I use. Mercedes uses this for their cars with 10k mile oil change intervals. Porsche uses it also I think. I noticed no difference.

Raymund

UPDATE

I've gone ahead and changed the oil.

oil pressure comparison taken from autometer gauge

Mobil1 10w-30 @ 180F temp: 12psi/idle; 55psi/8k rpm

Mobil1 0w-40 @ 180F temp: 18psi/idle; 65psi/8k rpm

It definitely has more pressure during cold start-up at 65psi (10psi more than 10w-30). I don't understand why since it's rated as a 0w and Mobil claims it has a lower pour point temp than their 10w.

siisgood00

Wow, thanks for the numbers. That is a great alternitive to the 15w-50 that some people tend to lean towards for track use. Thanks again

Tweakmeister

interesting.

I stick with 5w30 myself (can't find the M1 5w40 anywhere).

you might also try the smaller JDM Hamp oil filters...those will boost pressures a good but as well.

743power

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tweakmeister &raquo;</TD></TR><TR><TD CLASS="quote">you might also try the smaller JDM Hamp oil filters...those will boost pressures a good but as well.</TD></TR></TABLE>

I had good luck with the 0w-40 in my integra.

An alternative to the HAMP filters, is an oem rsx S filter. Just make sure you tell the dealer its for an rsx, or theyll get all stupid like they usually do. . .

siisgood00

Raymund,
For your next oil change what do you think about switching back to the M1 5 or 10W-30, and run the RSX-S filter and then post all 3 numbers??

Gansan

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Raymund &raquo;</TD></TR><TR><TD CLASS="quote">I've been using the recomended 10w30 grade for my car and in the span of 3yrs. I've noticed, within that time, the oil pressure at idle and peak is now at a lower value. The car has 40k miles. The last 2 years, I've been tracking the car once a month. I'm thinking about switching to Mobil1 0w-40 considering it should provide better protection at both end of the spectrum compared to their 10w-30. The oil gets up to 250F at the track and I notice a drop in peak pressure at that temp. Will that extra bump in viscosity be of any help during racing? Since it's rated at 0w-40, I would think it would be adequate for daily driving as well? Anyone who has used an out of spec oil grade care to share the results be it good, bad, or detrimental?</TD></TR></TABLE>

Hello Raymund, haven't seen you in quite a while. Hope things are going well with you.

I would like to point out that what you are seeing is a completely normal result of a higher viscosity oil. The thicker oil is harder to push through the passages, which results in higher pressure. However, this is not the same thing as higher oil pressure from improving the oil pump's performance, or other "oiling" performance improvments. I would not make the assumption that the higher oil pressures you are seeing automatically mean better protection. Now I know that the oil film is thicker and more protective with higher viscosity oil, but I am talking about equating higher oil pressure with better oiling.

Some people make the argument that using a small restrictive oil cooler is better because it results in higher oil pressures. This oil pressure comes from the restriction of the flow and not from any improvment in oiling. You can see the similarity in arguments.

I would say the 40 weight oil is good to use, but not because the pressure is higher. The improvement is from the thicker oil film.

siisgood00

Good info Gansan.

0philstireservice

good point....also new fresh oil will have a higher pressure reading also......when the oil begins to break down the viscosity goes with it...its a slow process but it happens. Synthetic takes a longer time for the viscosity to break down........but under a load, such as racing, it will break down faster. That is why most racers use a 20w50 .....the first number is insignificant for racing in most climates......

PhucNguyen57

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tweakmeister &raquo;</TD></TR><TR><TD CLASS="quote">interesting.

I stick with 5w30 myself (can't find the M1 5w40 anywhere).

</TD></TR></TABLE>
YOu can ge tit at most Autozones or your local MBZ dealer.

Raymund

Glen, thanks for the explanation. Since the higher pressure is a result of thicker oil resistance to flow, I'm left wondering about oil flow rate and its effect on the bearings. I would imagine a thinner oil would seep through the bearings at a faster rate. If the oil thins out, I can see a drop in pressure and a failure to provide a constant stream of oil bearier causing metal contact? If so, I can see why a thicker film would provide a better barrier of lubrication due to the longer dwell time inside the bearings. This is why I wanted to bump pressure by using a heavier weight. Given the 40Ws slower flow rate within the bearings, the oil pump can build up enough pressure to make sure the bearings stay lubricated. Does this make any sense??

PS. My friend is short of instructors at his event and I'm sure you are more than qualified. It will be at ButtonWillow on May30th. It's a Friday but if you can make it email me at ray77777@aol.com