Cetane boost = MPG boost?

Joined
Feb 9, 2021
Location
Wisconsin
TDI
2002 Jetta Wagon TDI
Hello fellow TDI owners!

I am curious about the effects of cetane on highway fuel economy. I’ve been running 2Diesel in my ALH, and I’m curious if I would see a boost in fuel efficiency if I added Cetane boost to a tank of fuel. And if I do, would it be worth the dose of Cetane? I figure $10 for a 16oz bottle of AmsOil Cetane boost and about 1.6oz to treat a 16 gallon tank for ten doses at a dollar a dose. Since I am not knowledgeable when it comes to the cetane levels in standard D2, or really how Cetane works in general, I’d be grateful for any knowledge y’all can share about this topic! :)

Thanks!
 

lemoncurd

Veteran Member
Joined
May 24, 2019
Location
Vancouver, WA | Willimantic, CT
TDI
MK6 Jetta SloWagon TDI (Golf Varient)
I am on the line between fuel additive is snakes oil or it actually does something. When I run additive its always power service (power stop?) and its the grey bottle. I swear the butt dyno says its a tiny bit quicker and that my trip odometer goes just that much further.
So yeah, I would say it does improve MPG some what! That stuff also has the added benefit of lubing the fuel system, which if you have a hand grenade of a HPFP like I do (CP4) then that would mean alot
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
It almost never pays for itself when used as you are wishing to. You will never prove it helps economy to any great extent. Same for lubricity. Easy to prove if it works for cold temps though and is useful in that regard. Cetane also has a point of diminishing returns. Adding more and more doesn't just keep increasing the gains. Because of that the better the fuel is to start with the less change you will notice. So just find a station that has good fuel. I am already using fuel with a small bio percentage in it so lubricity should be as good as any additive. I have tried most of the major additives back when and noticed no noticeable difference. Don't use a single one any more except for cold temps.
 

CleverUserName

Veteran Member
Joined
Oct 25, 2014
Location
NorCal
TDI
2014 OZ Cruze CTD & 2010 JSW 6MT & 2017 GMC Canyon CCLB ATX 2.8 Duramax
Boosting cetane does improve fuel economy if your fuel is below 50. After 50 it doesn’t do anything and if it’s significantly higher like 70+ it can actually reduce fuel economy as the peak cyl. pressure is reduced.
 

Stupendous60

Veteran Member
Joined
May 18, 2019
Location
.
TDI
.
I put 4oz Diesel Kleen cetane booster every other tank fill. Cars are smoother an have more pep especially when down to 1/4 tank and below. (less weight too) I love a cool rainy day under this circumstance especially! Cleaning advantages ang mpg increases? If it does, great.
 

bhanson

Well-known member
Joined
Apr 14, 2008
Location
Dayton VA - in the Shenandoah Valley near Harrison
TDI
2000 Golf TDI / Automatic Tranny
I cant definitely tell the difference between 50 Cetane and 40. Easier starts, more power. But, I've been surprised driving up and down the coast that I seem to get the same mileage on either. Now, Temperature, that impacts fuel economy. When it gets really cold out, my mileage drops by more than 10% on the highway.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Hello fellow TDI owners!

I am curious about the effects of cetane on highway fuel economy. I’ve been running 2Diesel in my ALH, and I’m curious if I would see a boost in fuel efficiency if I added Cetane boost to a tank of fuel. And if I do, would it be worth the dose of Cetane? I figure $10 for a 16oz bottle of AmsOil Cetane boost and about 1.6oz to treat a 16 gallon tank for ten doses at a dollar a dose. Since I am not knowledgeable when it comes to the cetane levels in standard D2, or really how Cetane works in general, I’d be grateful for any knowledge y’all can share about this topic! :)

Thanks!
the ONLY way to get better performance and MPG is to learn how to drive. get a scangauge II and learn how to be more efficient.
stay away from snakeoils.
 

Guttboy

Veteran Member
Joined
May 8, 2005
Location
Colorado at 7500'
TDI
Jetta MkV 2005.5 Platinum Gray/Gray Leather Pk2
Hello fellow TDI owners!

I am curious about the effects of cetane on highway fuel economy. I’ve been running 2Diesel in my ALH, and I’m curious if I would see a boost in fuel efficiency if I added Cetane boost to a tank of fuel. And if I do, would it be worth the dose of Cetane? I figure $10 for a 16oz bottle of AmsOil Cetane boost and about 1.6oz to treat a 16 gallon tank for ten doses at a dollar a dose. Since I am not knowledgeable when it comes to the cetane levels in standard D2, or really how Cetane works in general, I’d be grateful for any knowledge y’all can share about this topic! :)

Thanks!
For about 3 years from purchase, I ran Powerservice DieselKleen in the Jetta.

Then in 2010 I never ran it.

Car is bone stock and depending on who drives, it gets anywhere from mid 50 mpg (wife) and high 40s (me).

I do NOT baby the car at all and literally slam the pedal.

I just started running Powerservice again as we decided to keep the car due to a ton of factors. Will see if it makes a difference. However, running it consistently as the original owner we haven't experienced an issue with the engine whatsoever.

Did it make a difference? I am not sure. Not sure it hurts but at 200K miles and still going strong it may have helped.
 

Daemon64

Veteran Member
Joined
Jul 19, 2019
Location
Tyngsborough, Massachusetts
TDI
2015 Q5 3.0 TDI - Retired, 2021 Q5 55e PHEV
it never made an economy difference for me. The engine did seam a little quieter in winter weather, but thats about it. I took it as cheap insurance using Stanadyne and thats about it..
 

MukGyver

Veteran Member
Joined
Dec 11, 2020
Location
Sierra Ca
TDI
2004 Jetta PD
Using Power Service and 2-stroke oil and engine definitely runs smoother. mpg's doesn't seem to change much. I initially added too much 2-stroke evidenced by power reduction. I do periodic injector cleaner from the filter line too, at the cost of pd injectors just hoping to keep them clean and lubricated as long as possible.
 

Andyinchville1

Veteran Member
Joined
Apr 7, 2016
Location
Virginia
TDI
2003 Jetta TDI wagon, 5 sp, 226K miles
I have read that cetane boost does help MPG's of low cetane fuels up to a point.

I mainly use power service (gray bottle) at about 4 ounces per 8 to 9 gallon fill up (yes, probably way overdose but it's what I have been doing) AND Wal Mart TC3 2 stroke oil (about 4 oz per 8 to 9 gallon fill up).

My first injection pump made it to 315K miles .... it'll be interesting to see if this extra brew of "potions" helps the new pump last longer.

As far as MPG I have not experimented without running the extra additives with the new pump (I am at 430K miles now so the pump has about 115K on it so far).

Andrew
 

MukGyver

Veteran Member
Joined
Dec 11, 2020
Location
Sierra Ca
TDI
2004 Jetta PD
I think the stuff I use is the same. Super Tech Outboard 2-cycle oil TC-W3 ashless .. ("Blue juice") HFRR 474
 

Tom in PT

Veteran Member
Joined
Jun 7, 2017
Location
Twilight Zone, WA State
TDI
2005 Passat sedan - SOLD; 2013 Passat DSG; both purchased new
I have gone back and forth on additives and stopped using them in the Passat a long time ago. I have verified over a standard route I drive (about 27 miles from my house to a particular intersection) that the right foot mod and paying real close attention to your driving habits makes a huge difference in mileage, WAY MUCH MORE THAN ANY ADDITIVE WILL EVER GIVE YOU. If I pay no attention whatsoever to mileage, when I reach that intersection I am at around 44-45 mpg. If I pay strict attention to my habits, 50-52 mpg. This is the same weather, traffic etc. Hilly rural terrain, speed limit 40 then 55, with the first 5 miles being terrible stop and go, lights, uphill, etc. 2013 Passat, DSG, bone stock, emissions fix, summer fuel.
 

MukGyver

Veteran Member
Joined
Dec 11, 2020
Location
Sierra Ca
TDI
2004 Jetta PD
I dont do additives for mpg. If there is any power gain i agree its insignificant especialy with my stock motor.
 

kjclow

Top Post Dawg
Joined
Apr 26, 2003
Location
Charlotte, NC
TDI
2010 JSW TDI silver and black. 2017 Ram Ecodiesel dark red with brown and beige interior.
Someone on here did a fairly extensive study on additives and came away with Optilube offering the best boost in lubrication and slight boost in efficiency. If you search for optilube, you might find the original thread. It got rather long but I beleive the OP summarized everything back into his first post.

From my experience with my 2000 Beetle, I did not notice much difference using additives when still running Low sulfur diesel. I did not go back and look at additives after ULSD was forced on us in 2006. The only time I use an additive now is when heading to colder regions in the dead of winter.
 

MukGyver

Veteran Member
Joined
Dec 11, 2020
Location
Sierra Ca
TDI
2004 Jetta PD
If I didn't have a case of PS DK sitting in the garage I would switch over to Optilube because it seems to be the top recommendation on the site. I trust the numbers. I think PS is okay tho. It is definitely quieter at the top end (injectors) and that tells me it is lubricating.
 

Tom in PT

Veteran Member
Joined
Jun 7, 2017
Location
Twilight Zone, WA State
TDI
2005 Passat sedan - SOLD; 2013 Passat DSG; both purchased new
Around here (WA) in winter the refiners blend in Diesel # 1 which flows better in ultra cold temps, but that hurts mileage a lot. I throw in some PowerService in my diesel truck and a little Archoil for lubricity and keeping the fuel fresh since it sits for most of the winter. Probably not needed anyway.
 

kjclow

Top Post Dawg
Joined
Apr 26, 2003
Location
Charlotte, NC
TDI
2010 JSW TDI silver and black. 2017 Ram Ecodiesel dark red with brown and beige interior.
Blends with #1 are mostly in ALaska and Northern Canada. Winter blend is a misnomer. It's really accomplished through additives done at the tanker filling sites. That's part of the reason that I don't see a need to use additives on every tank. The station should already be doing their piece.
 

CleverUserName

Veteran Member
Joined
Oct 25, 2014
Location
NorCal
TDI
2014 OZ Cruze CTD & 2010 JSW 6MT & 2017 GMC Canyon CCLB ATX 2.8 Duramax
Blends with #1 are mostly in ALaska and Northern Canada. Winter blend is a misnomer. It's really accomplished through additives done at the tanker filling sites. That's part of the reason that I don't see a need to use additives on every tank. The station should already be doing their piece.
Two different types of additives.

Additives to prevent gelling are solvents like naphtha.

Additives to improve performance and enhance diesel fuel qualities should not be solvent based and aren’t added at the tanker filling sites.
 

ZippyNH

Veteran Member
Joined
Apr 22, 2015
Location
Southern NH
TDI
2015 JETTA TDI SE
Blends with #1 are mostly in ALaska and Northern Canada. Winter blend is a misnomer. It's really accomplished through additives done at the tanker filling sites. That's part of the reason that I don't see a need to use additives on every tank. The station should already be doing their piece.
Maine and NH has #1+#2 blends at some stations... IRVING is typically one.
Costal Maine usually has straight #2, treated, with blends sold as you go slightly inland....
And yes, when you spill it when fueling you notice the difference, as you do in mpg, and sometimes even a color difference with it generally being clear...
Additives ARE generally effective, but usually there are one or two extreme cold snaps that results in fuel gelling with treated #2....it can only do so much. Guess you can carry a bottle of the RED de-gel, but while it will do wonders melting it down, it is hard on the fuel pump due the alcohol.
 

kjclow

Top Post Dawg
Joined
Apr 26, 2003
Location
Charlotte, NC
TDI
2010 JSW TDI silver and black. 2017 Ram Ecodiesel dark red with brown and beige interior.
Didn't know that about Maine and NH. I remember years ago sitting outside the Toronto airport and noticing that the shuttle busses had switched over to #1. Talk about a stink!
 

High miler

Member
Joined
Mar 7, 2022
Location
Port huron
TDI
1.9 tdi
BEST darn stuff to run,and I run every tank,is HOT SHOTS SECRET DIESEL EXTREME. Been running it for a few years in my 2003 jetta and get 47mpg,I am not easy on pedal either 😆 with Amsoil 5w40 signature series DIESEL oil,Amsoil severe gear 75w90 in the 5 speed gearbox,made it shift better and smoother.
 

nicklockard

Torque Dorque
Joined
Aug 15, 2004
Location
Arizona
TDI
SOLD 2010 Touareg Tdi w/factory Tow PCKG
BEST darn stuff to run,and I run every tank,is HOT SHOTS SECRET DIESEL EXTREME. Been running it for a few years in my 2003 jetta and get 47mpg,I am not easy on pedal either 😆 with Amsoil 5w40 signature series DIESEL oil,Amsoil severe gear 75w90 in the 5 speed gearbox,made it shift better and smoother.
Just a warning for you since you are new: all Amsoil sales pitching is restricted to the 1 Amsoil thread and nowhere else. Also, your post seems like a billboard, which we frown upon. If I see anymore like this, I'll mark you as a spammer and you'll get a lifetime ban.

--moderator
 
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