Newbies and Vets: Tips for better fuel economy!

[boutmuet]

Still trying to find cetane numbers for 76/Conoco/Phillips 66, I just emailed them. Will post response when I get it.

 

[boutmuet]

Hate to post again but it is a pretty safe bet that the cetane levels for Chevron would be the same as Texaco right?

 

[ruking]

Would the cetane numbers be any different at a Chevron than is selling #2 significantly less than other Chev's in the area?

For example a Chevron has #2 for $2.85 while just a few blocks away another Chevron is selling #2 for $3.09

The answer is probably not, but on the other hand, it very well could be, however unlikely.

The law is fairly clear that ALL ULSD sold as ULSD has to be a minimum cetane (40 cetane and (15) ppm sulfur. Since most D2 comes from common sources (pipelines to distribution points, etc,) the minimums are met on fungibility issues alone. Since there can be STIFF fines in the very rare cases they are even tested, and even more remotely, fined, they are delivered nominally 1 to 2 cetane points above the min (40 cetane) and the sulfur ppm @ 15 is normally app 5-7 ppm. This does not stop individual stations or brands from adding their own additives.

I have gotten D2 in 12 states and CN. @ the VERY best it is NOT clearly marked. More normally, there is not much verbiage beyond 1. D2 2. green silicone rubber hose covers 3. per gal prices.

In contrast, RUG to PUG can be delivered to the pump @ 90 ppm sulfur, even with the standard being 30 ppm sulfur. It has to be mitigated "OFF LINE" (aka, FEES) to 30 ppm. While this does not stop most from delivering RUG to PUG @ 30 ppm, fee mitigation allows for (real world) 90 ppm delivery !!?? So gassers not only burn more fuel per like model, they burn fuel that can be 2 times to 18 times "dirtier" than ULSD. Ironically they who burn the REAL dirtier fuel, refer to D2 as ... dirty.

 

[BleachedBora]

Interesting points ruking! For what it's worth I know that my information from Chevron is that they try to set themselves apart in the west, and they do have their own additives that they add to the standard brew. There is also Techron D in the Sacramento area which is over 50 cetane.

From what I understand from all my work on this is that the fuel prices are not so much set by the store owners but by corporate. Fuel prices are (generally) higher closer to the freeway, near amusement parts/shopping centers, etc... They are lowest at truck stops, or branded stations near truck stops. When there are large price fluctuations then some stations may lag behind (or ahead) of others in their price changes.

In any case, it's a very complex system; like tax codes or credit scores, no one will figure it out for sure in a lifetime!
-BB

 

[boutmuet]

Interesting points ruking! For what it's worth I know that my information from Chevron is that they try to set themselves apart in the west, and they do have their own additives that they add to the standard brew. There is also Techron D in the Sacramento area which is over 50 cetane.

From what I understand from all my work on this is that the fuel prices are not so much set by the store owners but by corporate. Fuel prices are (generally) higher closer to the freeway, near amusement parts/shopping centers, etc... They are lowest at truck stops, or branded stations near truck stops. When there are large price fluctuations then some stations may lag behind (or ahead) of others in their price changes.

In any case, it's a very complex system; like tax codes or credit scores, no one will figure it out for sure in a lifetime!
-BB

Do you happen know if Texaco diesel has the same benefits as Chevron since they are the same company now? I know they put Techron additive in their gasoline now. Don't know too much about their diesel fuel but it seems like almost every Texaco station carries diesel which is nice for us.

 

[BleachedBora]

I'm not 100% sure, but from what I have heard Texaco/Chevron fuels are interchangeable. I fuel at Texaco from time to time myself when I can't find a branded Chevron station.

 

[Kymerik]

Alright, i hate to be ignorant and lazy, but...after looking around a bit, Ive noticed alot of nozzles are for the pre-2004 TDIs...could someone point me in the direction of the appropriate nozzles for my 2004 (looking for FE more than Performance)

 

[oEo]

Alright, i hate to be ignorant and lazy, but...after looking around a bit, Ive noticed alot of nozzles are for the pre-2004 TDIs...could someone point me in the direction of the appropriate nozzles for my 2004 (looking for FE more than Performance)

You don't want to replace the nozzles in your PD. Its a unit injector nozzle, they're a different animal! They're $$$. Biggest performance bang for your buck is a RC tune.

 

[Kymerik]

You don't want to replace the nozzles in your PD. Its a unit injector nozzle, they're a different animal! They're $$$. Biggest performance bang for your buck is a RC tune.

Ah that is starting to make sense...again forgive the ignorance, like ive said many times, first diesel learning the ropes

 

[boutmuet]

Emailed the cetane levels for 76 branded stations. The California Diesel Fuel that ConocoPhillips distributes through the 76 Branded stations has a typical cetane number of 47-53.

 

[S_Sanders]

When did that happen? Last time I was in Birmingham I saw several Chevrons with diesel, and the one up the road from me in Batesville, MS also offers diesel.

I hesitate to reply to a post that's six months old, but I live just south of Birmingham, AL and the Chevron station on Hwy 31 S near I-65 in Alabaster is still selling Diesel fuel. Today's price was 2.85 / gallon.

 

[S_Sanders]

My 2 cents... or more.

Wow, that's a lot of information to take in! Hopefully I can add some useful information to this long discussion.

As a newbie to the forum and the proud owner of my first TDI, I would like to thank everyone for the great information in this thread. It's been a very interesting read.

I saw comments about K&N air filters causing problems with MAF sensors. I learned a rather expensive lesson about this when I owned a 2002 Subaru WRX wagon. The first 50,000 miles with the K&N replacement filter were uneventful, but when I serviced the filter the instructions were vague about how much oil to apply to the filter. Well, I used too much and the result was a MAF sensor fouled by excess oil from the filter. I considered this to be a maintenance error that was my fault, not a problem with the K&N filter itself. The K&N filter that I bought for my TDI (replacement filter, not cold air intake cone system) says to use 1 fl. oz. of oil when servicing. I've never seen this type of info on their products before, and I suspect that they have realized that they need to provide details to prevent excessive oiling. This forum is the only place that I've ever seen negative comments about K&N products, and now I'm not so sure about using it in the TDI.

Regarding tire inflation, years ago my uncle taught me the following method and it has always worked well for me:
Quit worrying about how many pounds of air pressure to use. Instead "read" the tire wear and let it tell you how much pressure is needed. Over-inflation causes the tread to become too round and lift the edges of the tread from the ground (excessive center wear). Under-inflation causes the center of the tread to lift (excessive edge wear). Every tire will require slightly different air pressure for "proper" inflation based on the load it is subjected to. So, here's my uncle's method for finding proper tire pressure:
1) Inflate to something close to the max cold pressure listed on the sidewall. You might want to also wash the tires, including the tread.
2) Go for a drive. (Interstate is best, but avoid "twisties".) The purpose of this is to be able to visually see the edge of the tread contact area. (There will be a slight color difference and probably some dust from the road surface.)
3) "Read" the tire. The edge of the contact area should be at the point where the tread starts curving up to the sidewall. If the wear line does not reach this part of the tread, reduce pressure. If it is too far around the curve toward the sidewall, increase pressure.
4) Repeat steps 2 and 3 until you get the wear line in the right place.
Tire pressure will vary from car to car and from one set of tires to the next. Many variables are involved, but this method works well for even wear and max tread life. I suspect that it will be optimal for MPG too.

Also, use Nitrogen to inflate your tires instead of compressed air. Nitrogen is more thermally stable than compressed air, so seasonal pressure adjustments are not normally required. Another alleged fact is that oxygen molecules are just slightly smaller than the spaces between rubber molecules, so oxygen slowly penetrates through the tire. This is explains minor tire pressures decreases over time. The penetrating oxygen also contributes to tire deterioration by oxidizing all of the tire components as it finds its way out of the tire.

If any of you can confirm or deny any of this, please do. All of this is "to the best of my knowledge", but I can only guarantee that it's worth exactly what it cost you.

Sorry about the length of the post. Hopefully this will be useful information.

 

[ruking]

Wow, that's a lot of information to take in! Hopefully I can add some useful information to this long discussion.

As a newbie to the forum and the proud owner of my first TDI, I would like to thank everyone for the great information in this thread. It's been a very interesting read.

I saw comments about K&N air filters causing problems with MAF sensors. I learned a rather expensive lesson about this when I owned a 2002 Subaru WRX wagon. The first 50,000 miles with the K&N replacement filter were uneventful, but when I serviced the filter the instructions were vague about how much oil to apply to the filter. Well, I used too much and the result was a MAF sensor fouled by excess oil from the filter. I considered this to be a maintenance error that was my fault, not a problem with the K&N filter itself. The K&N filter that I bought for my TDI (replacement filter, not cold air intake cone system) says to use 1 fl. oz. of oil when servicing. I've never seen this type of info on their products before, and I suspect that they have realized that they need to provide details to prevent excessive oiling. This forum is the only place that I've ever seen negative comments about K&N products, and now I'm not so sure about using it in the TDI.

Regarding tire inflation, years ago my uncle taught me the following method and it has always worked well for me:
Quit worrying about how many pounds of air pressure to use. Instead "read" the tire wear and let it tell you how much pressure is needed. Over-inflation causes the tread to become too round and lift the edges of the tread from the ground (excessive center wear). Under-inflation causes the center of the tread to lift (excessive edge wear). Every tire will require slightly different air pressure for "proper" inflation based on the load it is subjected to. So, here's my uncle's method for finding proper tire pressure:
1) Inflate to something close to the max cold pressure listed on the sidewall. You might want to also wash the tires, including the tread.
2) Go for a drive. (Interstate is best, but avoid "twisties".) The purpose of this is to be able to visually see the edge of the tread contact area. (There will be a slight color difference and probably some dust from the road surface.)
3) "Read" the tire. The edge of the contact area should be at the point where the tread starts curving up to the sidewall. If the wear line does not reach this part of the tread, reduce pressure. If it is too far around the curve toward the sidewall, increase pressure.
4) Repeat steps 2 and 3 until you get the wear line in the right place.
Tire pressure will vary from car to car and from one set of tires to the next. Many variables are involved, but this method works well for even wear and max tread life. I suspect that it will be optimal for MPG too.

Also, use Nitrogen to inflate your tires instead of compressed air. Nitrogen is more thermally stable than compressed air, so seasonal pressure adjustments are not normally required. Another alleged fact is that oxygen molecules are just slightly smaller than the spaces between rubber molecules, so oxygen slowly penetrates through the tire. This is explains minor tire pressures decreases over time. The penetrating oxygen also contributes to tire deterioration by oxidizing all of the tire components as it finds its way out of the tire.

If any of you can confirm or deny any of this, please do. All of this is "to the best of my knowledge", but I can only guarantee that it's worth exactly what it cost you.

Sorry about the length of the post. Hopefully this will be useful information.

Positively and absolutely do NOT use a K & N filter ! ( mineral oil/oiled media). Stay with the oem or aftermarket products. (Mann, etc.) They not only filter BETTER, (for a host of reasons) but the K & N filter lets dirtier air pass, in addition to letting mineral oil pass thru the system, the system is NOT designed to ingest/pass thru either. In addition, you might want to do a calculation as to how much per gal you are paying for mineral oil. I think the "per gal" price will shock you. As a yard stick, I bought a gal of FOOD grade mineral oil @ $18 per gal shipped (if memory serves correctly) for other purposes. This is not to mention the costs involved with fixing your Subaru for example. You probably could better tell us the cost and consequences.

As to the tire inflation, start off @ 85% of max side wall pressure. So for example my 2009 TDI Sedan comes oem with 51 psi max side wall pressure tires. OEM recommendation is 35 psi or happens to be 69% of max side wall pressure. So 85% would be 43/44 psi. You can adjust up/down from that point (for a host of reasons). A good graphic is to use black board chalk and put anywhere from one to 4, one inch wide (or so) marks across the width. So for example, if you use 4 marks, put them at the 9,12,3,6 o'clock positions. The feed back will be immediate and graphic.

 

[40X40]

Also, use Nitrogen to inflate your tires instead of compressed air. Nitrogen is more thermally stable than compressed air, so seasonal pressure adjustments are not normally required. Another alleged fact is that oxygen molecules are just slightly smaller than the spaces between rubber molecules, so oxygen slowly penetrates through the tire. This is explains minor tire pressures decreases over time. The penetrating oxygen also contributes to tire deterioration by oxidizing all of the tire components as it finds its way out of the tire.

You are confusing marketing hype with science. According to what you just wrote we can just put air in our tires and after a time all the oxygen will leak out leaving only the nitrogen. (air is 85% N already)

This has all been hashed out many times in the past on this forum and several fellows that you would call scientists have thoroughly debunked your assertions.

Welcome to the club , we've all (re)learned a lot here. Sometimes it isn't pretty. Listen to the old guys and ignore the doom and gloom prophets. And DON'T use a KandN filter.....


Bill

 

[ruking]

Right, if nitrogen is free and available, by all means use it. I personally would not pay extra for it, but do have a set of tires that sometimes get filled @ Costco (they have a policy of using only nitrogen). But... it is NOT worth the trip and cue in the lines to top with nitrogen. When I first got the new tires (filled with nitrogen) the oxymoronic thing is you check it just as much as air fills, just to make sure it functions as advertised. So you inadvertantly or advertantly let out the nitrogen in checking to see if it holds the same pressure longer... as advertised. !!??

 

[S_Sanders]

Positively and absolutely do NOT use a K & N filter ! ( mineral oil/oiled media). Stay with the oem or aftermarket products. (Mann, etc.) They not only filter BETTER, (for a host of reasons) but the K & N filter lets dirtier air pass, in addition to letting mineral oil pass thru the system, the system is NOT designed to ingest/pass thru either. In addition, you might want to do a calculation as to how much per gal you are paying for mineral oil. I think the "per gal" price will shock you. As a yard stick, I bought a gal of FOOD grade mineral oil @ $18 per gal shipped (if memory serves correctly) for other purposes. This is not to mention the costs involved with fixing your Subaru for example. You probably could better tell us the cost and consequences.

I don't understand the relevance of the price per gal of mineral oil. There is no consumption of mineral oil with the K&N filters. A small amount of oil is applied to the clean filter before installation, but none is consumed. The problem with the Subaru was that I put too much oil on the filter after I washed it. A very small amount of oil was pulled off of the filter and it got on the MAF sensor. I replaced the sensor and all was back to normal. The problems that I experienced were not because the filter was a bad product, it was because I put too much oil on it after the normal cleaning service. As far as I'm concerned that was a maintenance lesson leaned.

 

[S_Sanders]

You are confusing marketing hype with science. According to what you just wrote we can just put air in our tires and after a time all the oxygen will leak out leaving only the nitrogen. (air is 85% N already)

This has all been hashed out many times in the past on this forum and several fellows that you would call scientists have thoroughly debunked your assertions.

Welcome to the club , we've all (re)learned a lot here. Sometimes it isn't pretty. Listen to the old guys and ignore the doom and gloom prophets. And DON'T use a KandN filter.....


Bill

Bill,

This is exactly why I said that it was worth what it cost you. It's so hard to separate hype from fact these days. I try not to repeat hype, but I'm not an expert.

The K&N filter warnings puzzle me. They guarantee warranty compliance and their filter media is proven to be less resistant to air flow (given equivalent surface area). This is the first time that I have ever found any negative comments about these very popular air filters. One local TDI owner that I know has been using one in his Jetta for years and strongly recommended that I get one for my car. I expected this to be a very popular enhancement. Can anyone add any further explanation for the warnings? (I'm talking about the replacement filter element that goes in the factory air box, not the cold air kit that replaces the factory air intake system.)

Thanks.

 

[40X40]

The stock filter poses NO great restriction to the TDI engine and it filters to a much finer degree. So the factory type filters are the smart way to go on these cars. They only have to be changed every 20,000(EDIT, I was wrong, it is 40,000) miles anyway.

http://www.tdiclub.com/search/?cx=0...b_5c1pjk8&cof=FORID:11&q=kn+filters&sa=Search

As you can see, there has been a long discussion on the subject.

I would suggest that you spend a couple of hours a day reading every sticky you can find. This will take a long time.... sorry, but it is worth it.

BTW, I have N in my tires, but it came with the tires.. I did not and will not willingly pay for psudoscience.

You are welcome!

Bill

 

[ruking]

Indeed I change my "stock" air filter every 60,000 miles. Also resist the urge to "check" the air filter between changings (no matter what intervals you decide), by dismantling the air box. "Breaking" the seals further induces the chances that it will not reseal correctly, thereby increasing the chances of a silicon particle leak.

 

[S_Sanders]

Just for the record, I did attempt to find old posts about K&N filters before I mentioned them. Perhaps my inexperience with the forum search was a factor, but I didn't find anything. Sorry to reopen an old issue.

 

[BleachedBora]

Best way to search (IMHO):

www.google.com

insert your search term here site:forums.tdiclub.com

So for example (clickable):
K&N effectiveness site:forums.tdiclub.com

 

[white95v6]

i wonder what a shell or a bp truck shop has for cetane levels.

 

[billyz]

I am driving a 2010 TDI JSW with stock 16" hankooks. I just dove a 30 mile stretch which was relatively flat a few very gentle rolls. On cruise control at 65 mph. I turned the A/C on / off. invariabally I lost 2-3 mpg with AC on. If I was at 47 mpg it dropped to 44. 45 drops to 42 etc.

 

[TedKurtz]

52.04 mpg over 78117 miles with '97 Passat TDI

Greetings,

I have owned three VW diesels, an '81 Rabbit, a '90 Jetta and a '97 Passat. I've loved them all. I live in Massachusetts and currently own a '05 Prius, which I bought after discovering that diesels were not available in Massachusetts because they did not meet emission requirements. That situation has changed with the new VW TDI's, and I plan to get a new Jetta TDI soon. Thus my interest in this wonderful site.

I am a fuel-mileage nut, and I keep a little notebook in each car with a pencil attached by a string. I record in this all my fuel purchases, noting date, odometer, amount of fuel and fuel price. I also keep a solar-powered calculator in the car which I eagerly use to calculate the fuel mileage for each refueling.

After discovering this site I totaled up all the fuel purchases I'd made while I owned the '97 Passat. It was 1501.2 gal for 78,117 miles. That turns out to be 52.04 mpg average for the total distance driven. Pretty good!

I do enjoy trying to get the best fuel mileage I can. I keep a light foot on the accelerator pedal and do not drive much above the speed limit. However, over a distance of 78,117 miles I was in lots of various situations. The winter-time mpg is a lot less that in the summer. I essentially ignored the tire pressures, letting the oil-change guys take care of that every 3000 miles. Thus the 52.04 mpg is not a remarkable achievement, just what anyone should be able to average with that car.

Another thing of interest is the effect on fuel mileage of breaking in the car. Conventional wisdom is that fuel mileage will increase as the car gets broken in. I break in my cars very carefully, following the instructions in the manual as carefully as I can. Net result? I don't see any significant change in fuel mileage as break-ijn process proceeds. For example, for 6 consecutive fillups in the first few miles I got 53.1mpg, 53.07 mpg, 50.26 mpg, 53.19 mpg, 55.76 mpg, and 49.85 mpg. After 20,000 miles I got 51.56 mpg, 48.36 mpg, 50.03 mpg, 48.73 mpg, 47.93 mpg and 48.95 mpg. I was probably driving with more of a lead foot after the break in was completed.

I look forward to owning another VW TDI and wonder what my fuel mileage will be for that car. I love the way diesels run, always smooth with lots of low-end torque. They start instantly on the first flip from the starter. I can hardly wait!

Regards,

Ted

 

[Ellery]

Total New-b

I am a 26 y/o pharmacist - live in Birmingham, AL - bough my first brand new car 8/09, 2009 VW Jetta Sportswagen TDI Automatic (wife cant drive a stick ) - prior to this purchase, I never would have paid this kind of money for a vehicle, but I wanted to make an investment of sorts to hopefully save money in the future with high fuel costs (they will go higher I am sure right).

I drive 100 miles round trip to work every day mon-fir to Tuscaloosa (roll tide btw ) - the terrain here is kinda rolling hilly like, nothing steep, just steady ups and downs on my commute to work on the hwy, 70mph limit.

Notably, I have not yet been topping off my tank, so I suppose my numbers based on the computer in the car could be way off so keep that in mind I guess.

I started off doing 75mph for a while, and noted that I may have been getting perhaps 37mpg, Just a month ago I decided to slow down and do better after my father in law bought the same car in NJ and was avg's 41mpg - highways there are mainly 50-65mph - so I slowed down to 65 and got more like 44mpg (again per my computer) - just this week I slowed down to 60mph and the computer reads higher, 49mph on the way to work the other day, on the way back it was raining hard and I only got 44-45mph (is there a best speed/rpm for rainy conditions - it seemed somehow that my MPGs were better at 65mph than 60mph??).

Anyway, a few questions about the content you all presented:

1) venting your tank - I dont quite understand - how do I go about this exactly and what do I need to top off the tank as you are suggesting I believe? At the moment I simply stop once the pump automaticallys stops which likely gives big variance im sure?

2) I assume based on reading through most all of this thread, that from an economics only standpoint, my best bet is to simply leave it stock, focus on the air filter, tire pressure, how I drive, and fuel choice to achieve optimal MPG's - the nozzles, turbo, and chips discussed I presume are a marginal economical choice??

3) How to drive - I heard alot about manual trannys, but what about my car - it has the shifter so to speak - any advice for how I should drive in the city - most of my drive is hwy with cruise control set going 60mph just a bit less than 2k rpm, but I obviously drive it also in the city?

4) I had not prior to this even thought about electronics? Do my electronics used (sterio for example, seat warmers, and the like) cause significant loss in MPG's. I believe if it is too hot, I am best to use the A/C if I must vs. rolling the windows down correct?

5) When going down a steep hill and applying the brakes consistently, my trans downshifts automatically, it will downshift and on somehills hit 3K rpm - I have since put it in the manual mode and left it in the highest gear (I am not sure exactly what speed I have, I think I have a 5th gear?) - any thoughts about this issue?

6) What MPG can I expect best from my car you think based on my location and make/model without any of the expensive additions discussed?

7) Just a thought on the issue of tire pressure - it seems you all recommend using a bit more pressure than my manual does I think - will that decrease the life of the tire - and if so, does that economic offset outweight the MPG economic gain?

8) You all mentioned skipping gears - do I try that in my trans even though it is an automatic?

9) Could you please recap the fuel additives - I was not familiar with the terminology you all used - B10, B20, or something, I dont know

Sorry for the lengthy post, I am totally, completely new with these considerations.

Any important points you feel that I missed would be much appreciated!

THanks, Ellery

 

[Ellery]

By the way, the car is technically my wife's also, we actually share it, but she really only drives it here and there, but it is city driving - Dont ask her to micromanage her driving, she will blow that off - bahh - I plan on once we pay this one off getting me another TDI if this one works out just to myself, perhaps a rabbit TDI....

 

[TedKurtz]

For: "Total New-b" Ellery

I can answer a few of your questions.

Venting the tank: I think the only reliable way to estimate how much fuel you're using is to keep long-term records. It is really not possible to determine how fully the tank is filled on one filling. Sometimes the pump will click off early and other times it will click off late. If the pump clicks early you'll calculate a high mpg, and if it clicks late you'll calculate a lower mpg. Over time you'll get a good idea what your mpg is. The tank has a vent tube, and filling to the vent means filling it till fuel spills out that tube onto the ground. The station owner will not approve of that.

Tire pressure: Raising the tire pressure reduces the rolling friction, a force that is almost independent of speed. Don't raise the pressure too much. The tire sidewall shows the maximum pressure for the tire, and this will be higher than is specified in the manual. Don't go above that maximum. Rolling friction has the most effect at low speeds. At high speeds air drag becomes the dominant resistance. Thus raising tire pressure will have most noticeable effect for around-town driving but won't effect highway mileage much.

B10, etc:

That the percentage of biodiesel in the fuel. B10 is 10% biodiesel and 90% petroleum diesel. I would not exceed the limit recommended by the Manual while the car is under warranty.

How to drive:

Diesels get their maximum efficiency at an engine speed pretty close to when the torque is a maximum. For the VW TDI I think that is a little less than 2000 RPM. Thus, shift and drive to keep the engine at that speed. Remember that every time you press hard on the accelerator pedal you are squirting more fuel into the engine. Make each squirt count. Don't use the brakes unnecessarily.

Ted

 

[billyz]

Just my 2 cents. I would not worry about "venting the tank" or trying to shift the DSG in the so called manual mode.

You cannot out shift that transmission. Do like you are doing, drive at a sane speed, keeps tires inflated. Nice , smooth transitions.

 

[Ellery]

Good - I have no intention of really messing with the DRG's "manual mode" - I find it strange and awkward to use anyway - some folks on this thread recommended skipping gears at times, but I think with the automatic it would be over the top perhaps, again, most of my driving anyway is highway, so likely no big effect.

I am just wondering if my wagon will really be able to get 50mpgs too? - I mean, my computer rated me a trip avg of 49 the other day to work, but most times its more like 44 and when I do my math today after refilling (just till the pump shut off automatically) I got 41.6mpg calculated - but I think I will keep tracking it now, I think it will get better with my more careful driving and perhaps a tad more tire pressure than the manufacturer.

 

[Ellery]

Also, I noted another thread on this site on the issue of "breaking in my car" - it now has 10K miles on it, during which time I did use alot of cruise control, but always some city stop and go mixed in there - I suppose the concept of targeting and maintaining 1900 rph ish very consistently goes against the whole "breaking in" concept, but I have spoken to many that refute this idea - in fact my manual essentially states the opposite...?? I should still just keep driving as I have I presume..?