huh... interesting. I've never really thought about it before but the molecules in metals are arranged in a crystaline structure. The structure is never perfect though and you have these voids/dislocations, grain boundries, etc. If you get near the resonant frequency or just vibrations will probably cause those dislocations to move around. I guess they could get to the surface and cause cracks making stuff break.

 

I know we have had issues in some of our race engines at tracks like Fontana and Texas where you are at a sustained high RPM for long periods of time but, we are talking small block chevys rarely going under 7500 RPM and up to almost 10,000RPM for 4 hours straight. Definitely not the type of stuff your typical street car is ever going to see.

 

89 mph

 

I read all you getting 25+ mpg. the best I have ever got was 23. I run 93 oct should I run the 91?

 

No, stick with 93. Octane does not improve gas mileage.

My Thanksgiving road trip I averaged 26.5 mpg and I drove 75-85 with at least 50 miles of it through mountains. Oh and BTW, I have a 50 trim, 272 cams and 780cc injectors.

 

I guess the stop and go really kills my mpg.

 

Yes it does...my city avg is about 19 or 20

 

Usually around 80 with light traffic

 

And then you move to Washington state and everyone is doing like 40-55 MPH in the 60 zone on a bright sunny warm dry day. When I do the speed limit, I feel like the lead vehicle in a police chase. I just know I'm going to get pulled over for doing 60 in a 60 zone just because I was travelling faster than the flow of traffic. SoCal was like +15->+20MPH more on the highway.

I've got this thing with school and playground zones, though. No speeding. Period. Its an absolute with me. I almost saw the death of an elementary school child on roller blades in a marked and active cross walk that I stopped for, but 3 other "drivers" couldn't wait and sped past me almost causing disaster in Dallas, Texas.

Now, not to say that the car just doesn't natually want to do like 80 or 90 or 100MPH because it just feels so right...

 

i average 80-90 and have never had a problem with any car of owned... i previous car i put about 15k in long trip highway miles going 75-95 the whole trip and traded it with 55k.. the car drove 110% since day 1...

maintnence is whats keeps the car fresh!

 

dude speeding is soo rice!! 5 mph so all the hoes can see me..

 

75ish

 

Interesting theory applied to the original question, but isn't the traditional mind set been that, "city driving" (continuosly variable RPM) is worse than "highway driving" (consistent RPM).

The stress exerted to maintain a moving motor (consistent highways RPM) would be less than the ones required to accelerate repeatedly (variable RPM).

 

75-80

 

I make the trip from fargo ND to minneapolis MN about 1-2 times a month... 3 hour drive