My Golf 2.0 petrol has just had it's 20K service. The dealer has filled it up with Shell Helix Plus oil. I have looked at the Shell website to check the viscosity of the oil and I *think* the picture rates it as 15/50. I can't find any other info on it. My concern is that, approaching winter, I would be better with a 10/40 oil. Can any oil expert out there confirm that Shell Helix Plus is in fact 15/50 and if this is a decent quality/spec oil for the car.
Thanks, Carl.
|
I think Shell Helix Plus is just a marketing name; it can come in a variety of viscosities. I have seen it as a 10W-30, 10W-40 and a 15W-50 and in Germany as a 5W-30. It is a 'synthetic technology' oil (I think that means semi-synth.) There is also Shell Helix Ultra (presumably fully-synth?).
The dealer will buy in a big drum, ring the dealer and ask what it says on the drum.
|
|
Thanks Aprilia. Have checked with the dealer and they use 10W/40.
|
|
I don't know what VAG recommend, but you might be better off with 5W/40 or 0W/40 which will protect the engine much quicker when starting from cold. I only use 10W/40 on very worn engines where the oil consumption would be too high with 5W/40.
|
Roger
Given that a 0/40 and a 10/40 have the same hot viscosity of 40 (which is much lower than the cold viscosity) why should a 10/40 reduce oil consumption compared to a 0/40? Surely you'd need to move to an oil with a greater hot viscosity eg 50.
Regards
John S
|
John, since many journeys are during the oil warm-up phase, about 20 miles, then the overall oil consumption will be significantly higher using 0W/40 than 10W/40.
0W/40 generally costs more than 10W/40 so using 10W/40 in a worn engine minimises the cost of oil. Using 15W/40 would further reduce the cost of oil but increase the fuel consumption during the warm-up phase.
|
RogerL, I think your assertions aren't well justified. 20 miles to warm up the oil? Even on a motorway (with no stop-starts) the engine gets warm much faster than that, say 5 miles, and I guess the oil at (maximum) 10 miles. In-town, where you have traffic lights, congested roads, etc, 20 miles seems like inter-city travel, so it then is a function of time rather than distance travelled. Weather is also a factor, but I'd say that when the fan pops in, after maybe 20 minutes, the oil must be rather warm, not hot, but warm enough.
Now, if you take into account the time it takes you to get to your frequent destinations (I'd say mainly work/office) and the driving conditions, you can reach to (some) conclusion about your oil consumption.
Besides, the 'w' number on oils is the viscosity index at a temp well below 0 C, so most of the time, before starting your (cold) engine the oil is already less viscous than the 'w' number suggests, and I'd say there is no significant difference between '0w' and '10w' in normal weather conditions. You need the '0w' when it can get real cold.
Vagelis.
|
Vagelis
You beat me to it!
You are right. The 'hot' viscosity is going to be far more significant even on relatively short trips than the cold viscosity, since the oil temperature rises very quickly from cold.
Regards
john S
|
|
|
-- previous post PS --
I mean, if it took so long to warm up, some guys with Audis would see the oil-light light up together with the fuel light, and refill both at the gas station!
Vagelis. ;->
|
|
Whether it takes 10 or 20 miles to warm the oil up in irrelevant in this case. The car concerned, typically, does 5 miles from cold each trip. From experience we know that the cooling fan ONLY comes on during long runs, in warm weather, in traffic jams. It NEVER comes on under normal circumstances. Use of top grade 10W/40 throughout this cars life, when 15W/40 or 20W/40 was fashionable, reduced the cold start wear and meant that it never burnt oil (didn't need topping up between oil changes) until recently. We now have to add a quarter litre every 1000 miles so we'll stick with 10W/40 as the most cost-effective grade to use. We know that oil is burnt on the rare long run but reducing oil consumption here has a negligible effect on running costs.
|
|
|
|
Vagelis, I as quite surprised when after recently changing the instrument panel on my car for one from a higher spec model with oil temp guage to see the oil temp still below 50C when the engine had reached 90C temp. It can take about 10 miles on a normal commute run to see the oil temp up to 70C and sometimes, depending on traffic, airflow etc it doesn't reach 80C in less than 20 miles. Car has no additional oil cooler fitted so no interference form that area.
JohnM
|
Yes, indeed oil gets warm some time after the engine has wormed up. It is the pathways coolant and oil follow inside the engine that makes this difference, as well as the distinct roles the two have. Coolant is there to take the heat away, and until it reaches some temperature, it doesn't get to the radiator. Oil is there to primarily lubricate and secondarily cool down. The coolant travels through the hottest parts of the head, the oil only lubricates the moving parts.
BTW, oil consumption by means of burning it in the cylinder, only happens when the oil's viscousity is low enough for the seals to not be able to keep it, which only happens with the oil (and engine) hot.
But with the engine cold, the oil is rather viscous enough for the seals to be able to keep it from going in the cylinder. So, I'd conclude that oil consumption (burning it) happens only with the engine hot. So, it doesn't matter if you use '0w' or '10w'.
Just my thoughts, BTW.
Vagelis.
|
|
|
|
|
