Originally Posted By: mechtech2
Originally Posted By: OilGuy2
Originally Posted By: Merkava_4
You guys that have switched from conventional to synthetic, has your fuel mileage improved at all?
Yes,
definitely. Have a 2008 Nissan Sentra SER which has the same 4 cylinder 2.5 liter DOHC that is put into the Nissan Altima 2.5S. EPA is for 24 city and 30 highway. We were close to those numbers for the first few months until I changed out the factory fill and replaced with Mobil 1 5W-30 Extended Performance with a Mobil 1-110 filter and a 300 ml can of LubroMoly. The gas mileage increased to 26-27 city and 32-33 highway and has gone higher since then as the motor and car "loosens up". Currently, we get 28 mpg city and typically 34 highway but on longer trips of 50 miles or more, we've gotten a whopping 36+ mpg. The car has its own on board computer that calculates gas mileage and predicts how far you can drive until the next refuel. Highly recommend...great tool.
We are extremely pleased with this car which has a CVT transmission that Nissan warrants for 120,000 miles. There are no shift points because the transmission computer will optimally and seamlessly select between 62 different ratios. The car has paddle shifters and I have used them from time to time but you have to be a cyborg driver to best the overall shifting the CVT makes for itself. The engine hits maximum torque at just 2800 rpm so it takes very little throttle (electric, as well as the power steering) to make the car move out fast. There is absolutely no "shift" we can feel, unless I use the paddle shifters which reduces the shifting to just 6 ratios!
Current mileage for the existing tank, about 8/12ths used (LCD fuel tank indicates in 1/12th increments...nice) is 28.2 mpg. We live in Worcester MA. There are a ton of lights, lots of traffic and steep hills everywhere. We live at 1000 ft elevation, BTW, on a very steep hill. We can see Boston's skyline (40 miles away) from our yard.
Car now has 35,000 miles and is currently at 14,000 miles of a 15,000 mile Mobil Extended Performance fill and its running and economizing better than ever. There is no question that the Mobil 1 and LubroMoly have both had a hand in the ease of starting and the fuel mileage.
Also helping is the change in late 2010 to Continental Extreme Contact DWS 225X45X17 radials. They have 2-ply polyester sidewalls and a real, perpendicular true radial construction, along with 2-polymide(kevlar) and 2-nylon belts on the tread. I keep them at their 51 psi maximum and the true radial construction soaks up the bumps while handling is to die for and rolling resistance is as low as it can go. Great tires for wet and snow. Last winter had record snowfall here and we always made it to where we were going without a problem.
The improvements in fuel mileage may be subtle, but it was 10% initially and now exceeds EPA by 16% city and 20% highway.
Dino? Oh, you mean oil heat, right?
Definitely? Definitely NOT!
Break in accounts for a good increase in gas mileage, and so does the Lubro Moly.
Why artificially attribute any increase to synthetic oil??
Break in assumes there is wear. The Mobil 1 EP and LubroMoly in addition to MMO in the fuel have taken wear pretty much out of the picture. I'm not new to this and have been driving for 48 years. I've commuted distances with various cars, always do my own changes and select the products myself. The cars' computer told the story right from the initial change and as the cars engine got "polished" (not worn), the mileage has improved very slowly and gradually.
As far as 51 PSI is concerned, sure you can save some gas with high air pressure but you can't just randomly up the pressure on any tire. Most of the radials sold today are NOT true radials. The sidewall belts are at a "bias" or angle so the tire is not as compliant on the road and if you pump them up that high (IF they can take it), they'll ride like they were made out of granite and you'll chip your teeth!
If you want to save fuel for real, I suggest using a PAO based synthetic, preferably with an ester in it. (You have to read the Material Data Sheets) Be careful on the selection of tires. You want to get a true radial not a bias-radial and you want a tire with very high PSI capability. Nice to choose a low rolling resistance tire if you can but the characteristic I needed was excellence in snow and ice and the Conti DWS was THE TIRE to get. Put MMO is the fuel tank periodically to remove all traces of carbon from the rings, cylinder heads and valves. Try different brands of gasoline. Some brands will run better in your car then others. We found Shell and Gulf to work best in the Sentra SER. I also recommend putting a can of LubrMoly in with the oil change. Ester and Moly are the KEY to low wear and high fuel efficiency, while using a PAO based oil.
With over 14,000 miles on the current oil and only having to top off with
1 quart total in 14,000 miles, you cannot assume that there has been a great "break-in" and "loosening up" in this engine. At 36,000 miles, its drives as tight as when it was new.
My son has a 2002 Audi S8 with 147,000 miles. He runs a mix of lubricants I recommended and put in his car: 2 qts of 0W-40 M1 Euro, 2 qts of 15W-50 M1 EP and 4 qts of Shell Rotella T 5W-40 with a 300ml can of LubroMoly. It has an 8 quart sump. After 7,000 miles on the current oil, he has had to top off his 4.2L V8 with just 1/2 qt of oil. This is a 360HP motor with 147,000 miles and he gets fuel mileage in excess of the EPA ratings too.
Yes, I think the combinations of products, and maintaining tire pressures religiously, and getting a four wheel alignment done by a competent shop all contribute to better fuel mileage. In addition to the fuel mileage, the quality oils are also contributing to a lack of wear in the motors. Nice!
Even nicer: because we not doing oil changes constantly, we can take better care of other aspects of the cars. My son's 2002 Audi S8 looks like it just drove out of the showroom. It is a joy to change oil once every year to a year and a half and
always in the warm weather.
Once upon a time, knives were made out of carbon steel and they rusted constantly. Then they came up with stainless: no more carbon steel knives!
Once upon a time, we used to lubricate our cars with heating oil. Then they came up with PAO, Ester and Hydrocracking. No more heating oil with detergents in our cars!
The problem with Dino is that it breaks down too readily and it can't be lubricating as well if it is frying inside the motor on hot parts, allowing severe wear in certain areas such as valve train and camshaft. Another issue with Dino is that it contains paraffin which is the primary contributor to the problems with sludge that interferes with the distribution of lubricant. Therein lies the answer as to why synthetics contribute to fuel efficiency where Dino cannot. Sorry, but Dino is grossly inferior as a lubricant where there is high heat, and it begins to breakdown the day it is put into an engine so we rush to remove and replace it. Since synthetics do not behave this way, they therefore contribute to economy!
