I agree. That is why I have settled on a 0w20 oil. Many seem to think the Xw number is only important in cold weather. However, 40 deg. C is pretty dam hot at least where I live. The other benefit is reduced wear during warm up.quote:
Originally posted by 427Z06:
Therefore, although fuel economy improvement might be minor once the engine (in particular the oil) is up to operating temperature, the first 5-10 miles is where you'll see a major improvement in fuel economy with GF-4 oils. And even if the average drivers trip length was 30 miles, in cooler weather, on average, one third of of that trip benefits significantly from the GF-4 oils.
This is how you quote a long post.quote:
Originally posted by JohnBrowning:
Higher HTHS has nothing to do with increaseing HP or fuel ecconomy!!! ( ... )
Question: If this oil provides a thicker film than a petroleum 10W-40, then that would account for the decrease in fuel mileage compared to an SM petroleum 10w30 right?quote:
Best all-weather viscosity grade for gasoline engines in cars and light trucks that are driven on the street on a daily basis. Reduces turbo lag and provides more power and economy while providing thicker bearing oil films at operating temperature than a petroleum 10W-40. Best all-round, synthetic oil for stock or slightly modified engines in high- performance cars that are street-driven. Best choice to replace a 5w30 or 10w30, petroleum-based or other-brand synthetic oil if maximum durability is preferred. Acceptable for engines that are occasionally operated in extreme cold weather.
1) Thicker Film , Easier to pump.quote:
Originally posted by Clyde65:
Question: If this oil provides a thicker film than a petroleum 10W-40, then that would account for the decrease in fuel mileage compared to an SM petroleum 10w30 right?
Question: Are they saying in the above quote that their 10w30 protects an engine better than an SM petroleum 10W-40?
How can you have a thicker film with a lower viscosity?quote:
Originally posted by Rand:
1) Thicker Film , Easier to pump.
Ask Redline...quote:
Originally posted by Clyde65:
How can you have a thicker film with a lower viscosity?quote:
Originally posted by Rand:
1) Thicker Film , Easier to pump.
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Which leads me to question its credibility on modern oils and formulas ie redline.quote:
In API tests, the current specification is ILSAC GF-
2,
I agree the paper is a bit dated (appears to be written in 2000), and would be very happy if someone could point me to a newer one of similar technical quality. However, if you look at the introduction of the paper when the author sets the scene of where oil is going and why, I think he deserves the "crystal ball" award. Here we are in 2006 with Ford, Toyota, Honda, & Mazda recommending GF-4/SM 5w20 oil with an HTHS viscosity of 2.6.quote:
Originally posted by Rand:
Also the linked paper is pretty far out of date
Which leads me to question its credibility on modern oils and formulas ie redline.quote:
In API tests, the current specification is ILSAC GF-
2,
How can you put any credence in a research paper published in Feb. of 1981? Virtually no engines spec'd 5w20 for such severe service back then. And most 5w20s from that era were formulated for arctic type conditions, not severe service in normal temps.quote:
Originally posted by carock:
A test of 5-20W engine oil is "SAE #810330 Engine Oil Bearing Wear". It was found that for the taxi engines tested that thinner oils incurred more wear.
I agree it is real, but it just did not seem to make the list of where losses were identified. Some of the other tests had many other areas identified if you read the paper. However, HP lost to pumping didn't seem to make it as a signfificant item. Just a guess but I would think the oil pump may be in the fractional HP range, and you would be talking some relatively small % change in that fractional HP. These other losses depending on the RPM and load are in the 2 HP or so range.quote:
Originally posted by TooSlick:
Ron AKA,
How do you think the oil gets to these places inside the engine if not through pumping?
That's what they mean....
TS