Exxon Synergy Diesel Efficient, marketing from Exxon?

tikal

Veteran Member
Joined
Apr 18, 2001
Location
Southeast Texas
TDI
2004 Passat Wagon (chainless + 5 MT + GDE tune)
Well, now it is time to switch back to regular for a few thousand miles and see if it goes down!

Certainly that's a fair option to consider.

There is also the cost/benefit factor. If someone has base-lined their vehicle's MPG with fuel a and b sufficiently to move to fuel c, which is trending and averaging more than 2% gain in MPG vs fuels a/b, then there might not be a need to go back to those previous less efficient fuels.

I am curious, is there any other D2 fuel brands that have in writing a specific fuel economy gain statement?
 

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
I'll take a 2% increase any day. But, as suggested, it will hardly be noticed, especially on a small scale.

Below is a graph of fuel consumption of my formerly owned 2000 Jetta TDI from March 2002 to July 2011. Yes, this is one of numerous graphs I did, it is Ounces Per Mile. But, the graph looks exactly the same in MPGs or any other unit. (My son now owns the car and still gets over 50 mpg tank after tank at over 370k miles.)

Keep in mind, 99.99% of the time, I did a "complete" fill-up (vented) ...

EDIT: Notice, that the tank after tank fill-ups are fairly tight through March 2008... I retired, March 31, 2008. After that date, my driving habits and style changed.... (2.5 ounces per mile equals approximately 51.2 MPG)

 
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KevinGary

Veteran Member
Joined
Dec 6, 2017
Location
Long Island
TDI
2015 A6 TDI
I wanted to report back on my experience with Exxon Synergy Diesel. At the outset, let me say that I know that this is not a scientific analysis and that it is one person's experience.

I have 89K miles on my 3.0 A6 TDI. Almost all of my miles are commuting miles in the NYC metro area. I have hand calculated the mileage of every tank since new and have input it into an excel spread sheet. (yes I have OCD!). After 89k miles my overall MPG is 28.6563. During those 89K miles I used BP and Shell fuel exclusively. So I have a pretty good baseline for comparison.

In recent months I noticed a decline in my MPG and decided to give Exxon Synergy a try. I have now driven 1,136 miles on it and have averaged 29.2783 MPG, i.e. an improvement of .622 mpg, or an improvement of slightly better than 2% when compared to my lifetime MPG. This is about the same as Exxon claims. These last 1,136 miles were typical commuting miles for me. No extended highway trips.

Of course that it is comparing it to my lifetime mileage. However, remember that I told you that I had observed a drop off on MPG and that is why I tried Exxon Synergy. In fact, for the 6,619 miles before the switch my MPG had dropped to 27.272. The drop off started last August and when it happened I tried various fuel additives to no avail. By late September I stopped with the fuel additives and decided that the car was just getting older. So by the time I tried Exxon Synergy I had driven over 5,000 miles since adding any of the additives. Comparing the Exxon Synergy to the entire "dropped period" the mileage was 2.006 MPG better, ie 7.3% better.

Of course part of the entire "drop period" included the warmer months and the impact of the fuel additives. So I also looked at my MPG for the 1,150 miles before the switch. This roughly lined up with the same number of miles that I had driven with Exxon Synergy (1,136) and all of the miles were winter miles (January-March). During this period I averaged just 25.727 MPG on BP and Shell. When comparing that MPG to the 29.2783 MPG I got with Exxon Synergy, there was an improvement of 3.551 MPG, or 13.798%.

Based on my experience it seems that Exxon Synergy does a better job of cleaning the fuel system than the additives I tried (Stanadyne, Power Service, Liqui Molly and XPD) or the fuel offered by Shel and BP. It also seems to improve the MPG by .6 MPG in my car, or about 2% when compared to the lifetime MPG.

I know that this is not a scientific analysis, but I thought I would report my observations.
I have now used the new Exxon fuel exclusively for the last 4,276 miles and have averaged a hand calculated 30.16 mpg.

I have refined my "baseline comparison number" because I could not believe the improvement. My baseline number no longer includes the car's first 14,965 miles, which I removed because it was the car's break-in period where it averaged 26.28 mpg. I also removed the mpg that I experienced from 77,891 to 87,473 because this was the period where my mpg dropped to 27.38 that caused me to try the Exxon fuel to correct whatever was going on. After removing these two periods, I am left with the 62,925 miles between 14,965 and 77,890, when the car averaged 29.49 mpg. I think this provides a fairer "baseline".

Against this revised "baseline" the Exxon fuel provided a 2.3% improvement, which is more in line with Exxon's claims. But what remains amazing to me is that the Exxon fuel seems to have cleaned out whatever caused my mpg to drop to 27.28 mpg for the 9,546 miles between 77,891 and 87,437. During that period I tried Stanadyne, Power Service, Liqui Molly and XPD trying to clean out whatever caused my mpg drop, and none of them helped.

So, while still not a scientific analysis, the fuel does seem to deliver the claimed mpg improvements and provide an effective "detergent".
 
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asgoodasdead

Well-known member
Joined
May 6, 2019
Location
NJ
TDI
2011 Jettta Sportwagen TDI
a lot of exxon stations around here now carry this, but its always 40-60 cents per gallon more than diesel from any other station, so its impossible to justify buying for me
update: now the Exxon closest to me switched over to the Efficient and didn't change the price [emoji41] it's some of the cheapest diesel around. I'll be exclusively running it for now on

Sent from my PH-1 using Tapatalk
 

tikal

Veteran Member
Joined
Apr 18, 2001
Location
Southeast Texas
TDI
2004 Passat Wagon (chainless + 5 MT + GDE tune)
update: now the Exxon closest to me switched over to the Efficient and didn't change the price [emoji41] it's some of the cheapest diesel around. I'll be exclusively running it for now on

Sent from my PH-1 using Tapatalk

Great. Out of curiosity, how do you know it 'switched over'? New signs?
 

KevinGary

Veteran Member
Joined
Dec 6, 2017
Location
Long Island
TDI
2015 A6 TDI
update: now the Exxon closest to me switched over to the Efficient and didn't change the price [emoji41] it's some of the cheapest diesel around. I'll be exclusively running it for now on

Sent from my PH-1 using Tapatalk
Based on my experience you won’t regret it.
 

TurboDirectInject

Active member
Joined
Nov 6, 2015
Location
WNC
TDI
2006 Jetta TDI, 5 spd
I used to only fill up with Shell, and averaged around 39 mpg mixed city/highway driving.

Moved awhile ago and there are no Shell stations anywhere near my daily drive now. Switched to Exxon, and I now average 42 mpg mixed.

After moving I would seek out Shell's and fill up, so it's not the driving route I take since moving either. Post-move my MPG with Shell was still 39, and that was making special trips just to Shell. . . I slowly switched to Exxon after being lazy/in-need of fuel a few times and not being close to Shell. Only then realizing how much better MPG I was getting by doing so.

Before I switched I would get a fairly regular puff of diesel smoke after idling for a few minutes, I believe due to a sticking injector. Since switching to Exxon I have not been experienced the post idle puff once.

In my car (2006 Jetta) that is a 7.5% mpg gain, and it runs smoother. I'm sold. It costs the same as any other diesel around me. Paying $5.40 a gallon now makes every mile worth it. . . In terms of MPT (miles per tank) I essentially get a free gallon with every fill up at Exxon vs. Shell. (590-600 miles/tank Exxon vs 550-560 Shell).
 
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tikal

Veteran Member
Joined
Apr 18, 2001
Location
Southeast Texas
TDI
2004 Passat Wagon (chainless + 5 MT + GDE tune)
I used to only fill up with Shell, and averaged around 39 mpg mixed city/highway driving.

Moved awhile ago and there are no Shell stations anywhere near my daily drive now. Switched to Exxon, and I now average 42 mpg mixed.

After moving I would seek out Shell's and fill up, so it's not the driving route I take since moving either. Post-move my MPG with Shell was still 39, and that was making special trips just to Shell. . . I slowly switched to Exxon after being lazy/in-need of fuel a few times and not being close to Shell. Only then realizing how much better MPG I was getting by doing so.

Before I switched I would get a fairly regular puff of diesel smoke after idling for a few minutes, I believe due to a sticking injector. Since switching to Exxon I have not been experienced the post idle puff once.

In my car (2006 Jetta) that is a 7.5% mpg gain, and it runs smoother. I'm sold. It costs the same as any other diesel around me. Paying $5.40 a gallon now makes every mile worth it. . . In terms of MPT (miles per tank) I essentially get a free gallon with every fill up at Exxon vs. Shell. (590-600 miles/tank Exxon vs 550-560 Shell).
Thanks for sharing your experience TurboDirectInject. Approximately how many times have you fueled with "Exxon Synergy Diesel Efficient" to arrive at your 7.5% gain estimate?
 

TurboDirectInject

Active member
Joined
Nov 6, 2015
Location
WNC
TDI
2006 Jetta TDI, 5 spd
Thanks for sharing your experience TurboDirectInject. Approximately how many times have you fueled with "Exxon Synergy Diesel Efficient" to arrive at your 7.5% gain estimate?
I have been using it for about the last 6 months.
 

AndyBees

Top Post Dawg
Joined
May 27, 2003
Location
Southeast Kentucky
TDI
Silver 2003 Jetta TDI, Silver 2000 Jetta TDI (sold), '84 Vanagon with '02 ALH engine
So, if I switched to Exxon my 2003 with the ALH should get a 3 to 3.75 bump in MPGs? Hmmm.
 
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