Thought it was said breakin is within 10k.

Mines at 18k.

That's about what I got a while ago. Last year when I got my GT rims they came with a set of Kumho Ecsta AST 225/50R15s. Ever since then, instead of about 27 mpg, I've been getting 24 on average, and even flirt with 20 on occasion.

Well, one of the ASTs got a flat today and it's not repairable. So I'm going back to the stock size (or maybe 205/60R15), in Kumho KH16s. We'll see if my mileage gets better again or if it was just coincidence that the mileage got worse (and maybe I have some other issue).

WEll, once again real life trumps the book. I didn't start getting my best mileage until after the 30k mark. My best friend with th Sonata just turned 28 k and mentioned his mileage was better than he's gotten before as well. Coincidence? Maybe.

Oh, and my F-I-L with that just bought a Spectra5 was "complaining" that he's "only" getting 30-31 with stop-n go driving and a Jersey style to boot. He's getting ready for his FIRST oil change! I told him to be patient.

My Elantra seems to be getting better mileage with age too (now at 25K mi.). But I wonder if the gradual increase may also have something to do with tire wear? After 30K Bob, were you still on the factory tires, which would be quite worn by then? Consider the following:

A couple of weeks ago, I purchased a new set of Fuzion HR1's for my other car, a 2001 Passat. The Passat had been getting great gas mileage on OEM Continentals, which were quite worn, so I replaced all 4 with the Fuzions of the exact same stock size. I immediately noticed about a 10% drop in gas mileage. I upped the tire pressure from the 30psi the installer put in there, to about 33 or 34psi, where I normally like to keep it. Noticed maybe a slight improvement. I also noticed on the Passat's computer that the mileage would tend to increase a little after 20 or so miles on the highway. It had not noticeably done that before. I was using the same gas, same driving habits, driving the same stretch of hiway that I always do. The only difference was the new tires.

My thinking is the new tires provide much more "resistance" than the old worn Continentals (duh!), but I wasn't expecting such a dramatic drop in mpg. But after 20 miles or so of hiway driving, it seems to cut the difference in half. Perhaps because of the tire design, materials, etc., it performs better from an mpg standpoint after it really gets warmed up.

I know from this, as well as the Passat forums, that people who increase the wheel/tire size (especially the width), often experience a dramatic change in mpg. But I used the stock tire size. I thought about trying to blame the mpg loss on seasonal gasoline differences, but I live in FL. Also going from a winter (if you can call it winter here) to a summer formulation would tend to improve mpg, so I don't think that's it. Also, the Elantra would be experiencing mpg loss too, since I fillup both cars at the same station.

My conclusion, and point, is that don't underestimate the tires (condition, wear, style, inflation, etc.) when looking for those mpg villians. I really believe they can make a difference (perhaps as much as 10% or more).

My first tank of fuel in my 08 elantra got my 26 miles per gallon. That was mostly in town driving. I was pretty happy with that.

On my first tank (bought car 31 March), not trying for great MPG and with a lot of around-town, I got 36.6. I had to check my numbers three times, I was (happily) flabbergasted.

Today's fill-up showed 31.0. But I believe this tank had ethanol (puke) in it. State just slipped it in a couple of weeks ago.
I'm expecting 40+ on the highway. On real gasoline.

I see some folks see an improvement using premium.
Once I burn off this crap/makebelieve gas, I may try 9 gallons of the Good Stuff if it actually has a + effect on MPG.

Good luck on the 40 mpg highway. I think the 36.6 ya got was amazingly good (especially since it included some city) and close to the upper limit of what you'll get. As far as premium, in the long run, it makes little sense with our cars. Stick to 87 octane.

Guess the autos have advanced some in the last few years.
Mine short-shifts like it was born to it, and as it gets warmed up it shifts at lower RPMs. When cold it shifts 1-2 at 2500 or so, but I've seen it shift at under 2000 RPM when warm and I'm not in a rush.
I also coast to lights or stop signs, providing there's nobody back there who I'm going to hold up.

Actually, my factory tires have been gone since 10k miles. at 30k I was on 215/45/17 Nitto NT 450's. At 60k I was on the 205/55/16 KH16's. I do notice a differnce between the KH16's and the 225/45 Hankook RS-2's. The 'kooks are stupid sticky and my weekly average will drop to around 29/30 on a race weekend. The wife drove the car last week and averaged 34.3mpg last week and had a 412 mile tank.

I have had my 08 Elantra for about 4 weeks and i'm on my third fill up. I got about 31.5 mpg on the latest tank with about 60% being in town driving. I can live with this especially when i was getting about 13-14 in my 00 Silverado. I had to keep the truck, although i don't drive it but once a week, because i own a house with two acres and every man needs a truck. I can't handle the in-laws that want to borrow it every weekend to haul the mulch or shrubs. Get your own!!!! The Elantra is much funner to drive and easier to park then the "extended long bed tank."

Big V

I'm getting 30.4 mpg in mixed driving 40% city , 60% highway. I just had my second tank of gas and because of summer had my AC ON. Interestingly I didnt see any difference in mileage when I had AC ON v/s AC OFF. So far it is bit below my expectation of 32+mpg but mine is just 500 miles old so I think it might improve.

Thats good MPG. I'd be estatic if i got 32 with that much city. I get average of 27.