seattle951

I took my 951 out of mothballs today for drive and was surprised about how cool it was running. I am wondering how much impact moving to Royal Purple 10W-30 XPR racing oil had on temperature. RP claims that it is signficant.

It is 45 degrees in Seattle today. I had the heater on at a low setting. I drove the car for an hour and the temperature guage read:

• Extended idle: Just under half on the gauge with no cooling fans
  
• City driving: First hash mark
  
• 70 mph freeway driving: halfway to first hash mark

About the car:

- 2500 miles on rebult motor
- New radiator
- Water wetter
- Additional external oil cooler
- 16 PSI max boost
- 14.7 AFR off boost
- 11.9 AFR on-boost

Oil pressure: 3.75 at idle, 5.0 at light throttle.

The RP has completely eliminated all engine noise at start up. It might be my imagination, but the engine seems smoothier and slightly more responsive.

RP's ads claim a drop in operating temperatures. I took this with a grain of salt since it could be marketing hype. I am beginning to think otherwise.

Does anyone have experience with RP XPR reducing operating temperatures?

Is it actually harmful for the car to run too cool since it was designed to operate at a specific temperature range?

Keithr726

I get about the same temps using valvoline 20w50 racing. I believe the owners manual says the first line is normal but I may be wrong. I must say that oil pressure at warm idle is impressive, mine is not close to that good.

David Floyd

In 45 deg temps or lower, my car stays at or just under the first white line, I run 5w40 Rotella syn during winter and I daily drive.

special tool

Probably what you are going to find out (eventually) is that someone elliminated the thermostat sealing ring.
It is much easier to install the thermostat without it, and it will give an approximation of 50% loss of thermostat itself altogether.

Of course I could be wrong...but better to bet WITH me. lol

PEvans

At one point I really researched this, and took some temperature readings on the 951 I had at that time. According to my notes the lower mark is supposed to be 80C and the upper mark is 100C. The fans are supposed to come on at 92C (slow) and 102C (fast). Measuring temperature at the water neck, on that car the lower mark was really more like 86C and at idle fans would not allow the temperature at idle to get above 97C and would cool it to about 88C, so keeping the temperature in the upper half of the range between the marks.

It sounds like your car is running cooler than that now -- at idle with the heater on and 45F ambient it never gets hot enough for the fans to come on. I am surprised that it is below the first mark when you are driving, though I don't think I have ever driven my 951 when it is in the 40s.

CarbonRevo

Is it just me...or anyone else iffy about RP products? Heard the motor oil is about the worst stuff you can run.

PEvans

Do you mean by this that more water passes around the thermostat, making the car warm up more slowly?

Is there any harm in this?

fbgh2o

My experience is very much like David Floyd's in the late fall (before I put the car away) it was running below the first line at speed, with no thermostat at all...

My idle oil presure is 4 bar (20w50).

ehall

It has nothing to do with the oil. It's winter.

seattle951

I drove a 924S in Seattle all year round for 3 years and it didn't run anwhere near as cool as this car. It ran closer to halfway mark and cooling fans would come on at idle even in the snow.

I would expect the two cars to be similar. That is why I was surprised at the 951 readings. Perhaps the 951 is just fresher than the 924S.

The 924S was completely stock with 64k miles. I sold the car two years ago to make room for a Mustang GT.

Techno Duck

I have a digital gauge hooked up to my upper radiator hose since August. I have never seen higher than 180-185*F running on the street and by then the fans kick on and it comes back down. Usually when cruising on the highway i saw around 160*F with ambient being around 60-70 degrees. Before i stopped driving the car i was seeing around 150 degrees cruising with ambient around 40-50 degrees back in November. The peak temp recorded by my gauge was around 195*F in October while running the car hard at Pocono. It was about 50 degrees ambient that day.

My dash gauge is usually under the 1st mark and i dont think i have ever seen it go past the 1/2 mark during normal driving, even in the dead of summer. Personally i think the dash gauge reads a little bit low. I have a theory that this is the same reason the gas gauge reads 3/4 of a tank on almost every late interior 944 i have ever seen. I think the needle slips on the peg a little bit after 20 something years causing slightly lower readings. Thats just my theory.. .

ehall

the 924s is a lot different.

gpan951

I live in Singapore and the temps here average 30 degrees Celcius or 86 degrees Fahrenheit during the day all year round-with the a/c running, the temp gauge is always at the first white hash.

INURGRL951

Each and every engine has it's own character to where it runs better at. But where it's "sapose" to run is just above the first thin line. For example there two 951 I got here one runs better alil warmer so I use a old style thermostat. The other runs better cooler (right in between the fat and the first thin line) and that one running a cooler thermostat with a lil hole drilled in it, more row costom radiator and water wetter. I rarely get to where even the fans come on!! I run castrol full syntec 5w-50 allyear oil p at 4 at idle warmed up.It also helps for when you track it then it get to the "normal" temp zone.

In all what you are saying sounds good to me

seattle951

From a cooling perspective, what is the major difference? The 924S has a 944 2.5L N/A engine. I believe there is some difference with oil cooler between the 924S and the 951. Is there something else that would allow the 951 to run cooler?