Embalmer

I'm happy to report at my second oil change I used Mobil 1 5W20 ($25 for 5 qt jug @ Wal-Mart) and was rewarded with a significant gas mileage increase. I have 7500 miles on the car and have NEVER reset the stats in my info center. I've recorded a cumulative 21.4 MPG since I bought the car in December. I changed the oil last week, then drove with a bunch of fellow Stangers 4 hours to Indianapolis for the World Ford Challenge, then drove home. Upon my return, my mileage had increased to 22.1 MPG! I was astonished because the driving to Indy was spirited, to say the least. Being as I've not changed anything else I have to attribute the increased MPG to the oil. Thoughts?

theedge67

I would think the mileage increase could be just the highway driving. 4 hours of highway driving, even though it was spirited driving at times, that is a lot of highway miles to add to the mpg mix. Keep driving it on your normal daily routine and see if it changes then, and then you can blame it on the oil.

Embalmer

In theory I would agree with you, but I live in rural central Illinois and most of my travel is highway. Just to prove my point, my average cumulative speed (again in my infocenter) is 43 MPH.

theedge67

What was the previous oil used?

Mustangfreak

So you gained 1mpg over $25 of oil. You didn't get the money back that you wasted on synthetic. The only way I can see you getting your money back is if you dont change your oil as often due to it being synthetic. What is it, 7,500 miles?

Plus now you always HAVE to use synthetic.

ShowGT

I run Mobil 1 and average 19.6 all the time around Kansas City

Francis

I run Mobil 1 in my 07 GT. I average somewhere between 16-21mpg, depending if I'm doing mostly highway driving or city driving, and if I do sprints in the hills around where I live.

bob

Naw, you can switch to and fro, it wont hurt anything, if you switch back to a dino oil, you just dont get the benefit of using a synthetic.

I dunno about you guys, but I'm none to gentle on my engine, I bought my car as both daily transportation, to stroke my ego, and placate that little lizard brain attatched to my spine, and even though I might never be able to justify the costs of synthetic versus fuel saved, I like the added protection a synthetic offers over the dino based stuff, that alone is my prime reason for using synthetic.

This reminds me of a buddy of mine who swore that CAM2 "pickled" a motor and if you broke the engine in on race fuel, you couldn't use anything else. Well, duh! If you use a high octane fuel to baseline the engine and then switch to regular gas, your gonna have to adjust for the change in characteristics and use a less aggressive tune.

Mustangfreak

Still waiting to hear one.......

Embalmer

I'm fairly sure the benefits of synthetic oil are proven:

Better protection over varying temperatures
Greater oil change intervals due to more uniform chains in the stock
Less breakdown over time and less sludge formation

I know that Ford's Semi-syn oil is excellent - I've used it in my Windstar for 100K with no issues at regular 5K intervals. I also have used Mobil 1 religiously in my 97 T-Bird and that motor was bulletproof, still running perfectly with over 120K. I just feel the Mobil 1 gives me added protection and if I don't get around to changing the oil exactly at 5000 miles, then I don't worry about the oil sludging up on me or something. The added MPG was just a bonus I felt mentioning.

ksguy73

My last car wasn't a Mustang but when I started running Mobil 1 it definentely ran quieter. I'm not sure about the gas mileage but it was quieter. That sold me on it and I will run it in my new 08 once it is broke in.

Zig-Zag

According to my records, I averaged 19.35mpg (over 40 fills) before I switched to Mobil1, and 20.57mpg (over 20 fills) after the change. Crunching the numbers, I saved about a gallon a tank, over 15 tanks to an oil change, comes to 15 gallons a change saved. 15 times a gallon @ $3 per is $45 a change. I don't know about you, but I sure don't pay a $45 premium for synthetic.

gremlin190

I actually noticed the same exact thing. I get the same gas mileage as you use to and you do now. However, driving at a steady highway speed for 4 hours could have swayed your results. I have seen avg's as high as 28 mpg driving on the interstate going ~75. Go 10 miles faster and down it goes to 24 mpg. No matter how I drive now, my mpg never stays below 21 mpg.

Tampa07GTCS

I hate you....my MPG has never been over 16 ...will changing to synthetic...help me?

kevinb120

You can extrapolate that to the longer intervals between oil changes as well using synthetic to technically further the savings. If you change it at 3000 mile intervals, you're actually throwing money away.

But its really hard to get any exact number, engines and drivetrains season, weather changes, and even the music on the cd player can change results

In theory, it can save you a little gas, I wouldn't use that as a main selling point for synthetic though.

metroplex

According to Ford they are now allowing 7500 mile oil change intervals using their 5W-20... I wouldn't push it that far, but based on my low annual mileage, I'm not spending a whole lot of engine oil (1 or 2 changes max).

From personal experience, synthetic oils have yielded little to no change in gas mileage.

rdw401

Although this was responded to above, I would like to chime in and say you can switch back and forth with no problem.

Synthetic can run much longer than petro. You can also change oil filters and just add a quart or so of make-up synthetic. You can even take a sample and have it analyzed to get an idea of engine wear etc.

Glenn

Glenn

gremlin190

I say give it a whirl if gas mileage is worth it to you, but you should take in account your driving enviroment. From what you get currently it seems like you drive in the city alot or you have a lead foot (which I can't blame you). IMHO I think it would help and the guys here say you can swith back and forth so it could be worth a shot.

The whole theory here is that we are freeing up some HP at the same rpm. If that is true, then we need lower rpm's to produce the same power to achieve the same speed. Lower rpm's equate less gas intake, hence the better gas mileage.