sandman

I am due for an oil change and was wondering what the best Mobil one would be for hot climates all year round.

Also I have a mild oil leak from the valve guide cover. Yesterday the oil leaked suficiently to put the needle on the lower end of the gauge. I noticed that the level kept changing as I drove specially when going down hill. Is this normal???

Thanks

Sandman

Jeff 993TT

15W50 will probably be your best bet for hot climates.

mike cap

Sandman,

Jeff is correct about the oil viscosity.

Your oil level gauge is acting normally. Read the owners manual regarding this gauge. It will only be accurate when the engine is at operating temps, on a level surface and idling for a minute or two. Otherwise ignore the oil level indications.

Mike Cap
1997 C2
Arena Red

Steve Weiner-Rennsport Systems

Sandman:

I'll affirm that 15w-50 is the best choice for your climate, hands down.

Personally, after 29+ years of working with 911's, I never believe the oil level gauges in any of them. IMHO, they are nothing but a "Red Herring' and mislead many people into making poor decisions about the proper oil level.

The dipstick is the ONLY thing that should be trusted, and as mentioned above, read and interpreted at operating temperature on level ground after idling for 2-3 minutes.

96P993

Would this be the same if you dont drive the car very much. I put at max 500-600 miles on the car a month. I would think with that little drivetime you would want to put in an oil that heats up quicker and gets to running temp faster...I could be completely wrong...opinions please

Steve Weiner-Rennsport Systems

Oil viscosity choice is really dictated by local environmental conditions and how the is to be used.

For these air-cooled engine's, I use and recommend 15w-50 for outside temperatures between 40 deg F and 130 deg F. For temps at or below freezing, the 10w-40 is better.

0w-40 is better suited for the water-cooled engines.

FWIW, most of the top level teams in AMLS running GT-3RS's use 15w-40. Naturally, this was the preferred choice for the 993 RSR's, too.

sandman

Thanks everyone

I think 15W-50 would be the way to go.

Sandman

fbfisher

Ironically, the tech at my local dealer also recommends 15-50.

Unfortunately, they only have 0-40 available. Go figure...he said that it in part has somthing to do with the design change in the lifters in the 996.

reed

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Steve Weiner-Rennsport Systems:
<strong>0w-40 is better suited for the water-cooled engines.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Steve,

Can you elaborate a bit? I have been using 0W-40 in my '86 930 thinking that the lighter oil would circulate quicker, especially to the turbo. I run the car only in the warmer months here in PA and would prefer the higher temp oil if there is no sacrifice in start-up protection. Thanks.

Steve Weiner-Rennsport Systems

Reed:

The 996 engine's clearances were optimized for the lighter oils and they do give the best fuel mileage. Further, the light oils flow better at low temps and this is important for minimizing wear when starting at outside air temps at 32 deg F and below.

The newest 996 engines with the VarioCam feature was specifically designed for the 0-40 synthetics and I would stick with that stuff in those engines. I am not sure that the cams will adjust valve timing the same way with the 15w-50 stuff, although this is yet to proven either way.

For the much-hotter-running air cooled motors, expecially Turbos', I stick with 15w-50. Don't forget that your oil temp guage only samples the oil temps at one place in the engine; its much hotter (and cooler) elsewhere.

emilios

Over here in Cyprus we have been getting very close to freezing temperatures in winter and high 40+ (degrees Celsius)in the summertime. On my 964 turbo 3.6 I use (Mobil 1) 0W50 during the winter months and 15W40 for the rest of the year. So far (touch wood) I haven't had or experienced any problems (no oil leaks, no strange oil temps or pressure).

993PET

Steve:

Can you comment on the 993 hydraulic lifter problem and oil viscosity. I was under the impression that 0W-40 Mobil 1 flowed better to the lifters particularly when the engine is cold.
I'm running 0W-40 in the spring and fall in Ohio and 15W-50 in the summer. I attend about 15-20 track days a year mostly in the midwest. I would also have to say that the top end on my car is noticable quiter when the engine is running on 0W-40.

Also what is your opinion on using Mobil 1 Delvac 5W-40 in the 993 Engine?, from everything I read this is the ultimate synthetic oil.

TIA

JF

97' 993 RS Look G50/21 going in next week

Steve Weiner-Rennsport Systems

JF:

I am unaware of any ongoing specific problems or issues with the 993's hydraulic lifters.

There is no question that these tiny precision machined parts are very intolerant of dirt and contamination and IMHO, the Factory recommended oil change interval is not sufficient to keep them clean. Further, some oils leave more deposits than others and contribute to additional lifter noise over time.

You are correct about 0w-40 oils lubricating things faster when its cold. Its simply a question of degree,........(pun intended).

All of the oil manufacturers publish viscosity vs ambient temperature charts for their products and one chooses an oil based on the range of temperatures that the car will be operated at. You've made an excellent choice of oil viscosity ranges for the temperatures that you are driving the car in.

I'd be interested in knowing how many miles are on your engine as most of these cars are quieter with 15w-50, rather than 0w-40.

I've not used Delvac so I have no input on that. Given the cost of the 911 engine, I've stuck with certain oils that I know to perform and protect the engine in certain regimes; street and racing from constant idling to over 9000 RPM operation. I cannot afford to take chances with our customer's or my own motor so I stick with Mobil 1, Redline, Kendall GT-1, and a few others.

993PET

Steve:

Thanks for your reply, my engine has 51,000 miles on it. I change the oil after 3 DE weekends and then at the end of the season for winter storage. Oil consumption is less than 1 litre per 3 DE weekends and or 2k street miles.

So you feel that 0W-40 in the colder months and 15W-50 in the warmer months is a good combination for the longevity of my engine cosidering where I live and how I use the car?

Do you know if the Mobil 1 available in Europe is the same formula as the Mobil 1 available here? I was told that the forumla for the US market was different to meet more stingant fuel consumption standards in this country.

TIA:

JF

jhb

I thought the "w" number referred to cold viscosity and the 2nd number was for warm viscosity. If that is the case, how could a 0w-40 and 15w-50 be that different once warm? Obviously, the 0w-40 will flow faster when cold.

I doing an oil change this weekend (my first) and plan to put in 0w-40. The car has 15w-50 in it right now. My car does a lot of small hops and a few larger ones and I only drive it seasonally with a few runs to keep things "wet" in the winter, so I thought this might be a good choice for me.

However, my car does smoke at start-up after it has been sitting a few days, and I think I may be eating some oil, but do not have a sense of that yet, I plan to keep an eye on it after the change. I would assume that it might smoke a little more with the 0w-40. BTW, i have 20k on the odometer.

Is my reasoning wrong here? Honestly, every time an oil discussion comes up I change my mind on what to use! I wonder if this is just over analyzing. Has an engine ever been damaged with street use with either oil in the tank?