tory negligence findings and the findings of no damages. The error chiefly complained of is the admission of evidence that Buchanan was driving at a speed of 80 miles per hour when he applied his brakes. Appellants are under the burden of showing, not only that this evidence was erroneously admitted, but that it influenced the jury to make findings they would not otherwise have made, not only upon the issue of Buchanan’s speed, but on the other controlling issues as well, not one of which even mentions Buchanan’s speed.
There was no jury finding that Buchanan was going 80 miles per hour, or at any other specific rate of speed, only that he was driving his car “at a greater rate of speed than a reasonable and prudent person would have driven it under the same or similar circumstances.” Appellants lay great emphasis on Pipkin’s testimony and argue that it must have persuaded the jury, not only to answer the speed issue as they did, but also to answer all other issues in such manner as to assure a judgment for the defendants. We find in the record no support for the latter argument. As to the speed issue, there was other testimony which, to our minds at least, was much more likely to induce the finding on speed than was Pipkin’s testimony. For instance, there was undisputed evidence that the weather was foggy or misty, that visibility was poor, that the highway was wet, but that nevertheless Buchanan “shot out of the fog” with his lights off and at such a rate of speed that, even after depositing 204 feet of skidmarks, his car struck the trailer with sufficient force to shear off the top of the Chevrolet and proceed completely under the trailer and 100 feet beyond it. This evidence alone, quite aside from Pip-kin’s testimony, would strongly support, if not compel, a finding that Buchanan was not driving at a reasonable and prudent rate of speed under the circumstances. Therefore, in our opinion, appellants have failed to carry the burden, imposed on them by Rule *434,* T.R.C.P., of showing that the alleged error “was reasonably calculated to cause and probably did cause the rendition of an improper judgment.”
Even if it could be said that Pipkin’s testimony did materially influence the jury to make the finding it did with respect to Buchanan’s speed, how can it be said that, but for such testimony, the jury would have made different findings with respect to Thompson’s alleged primary negligence, or with respect to Buchanan’s failure to keep a proper lookout, or his failure timely to apply his brakes? In our opinion, appellants failed in this respect also to show that the claimed error was harmful. See Cloud v. Zellers, 158 Tex. 253, 309 S.W.2d 806 (1958) and Flores v. Missouri-Kansas-Texas R. R. Co., 365 S.W.2d 379 (Tex.Civ. App., Dallas 1963, writ ref’d n. r. e.).
Appellants’ first seven points of error are overruled.
In Points of Error 8, 9, 10 and 11 appellants complain of the exclusion of part of the testimony of their expert witness, J. B. Carlisle. He was also an accident investigator and analyst, who testified that at the request of appellants’ counsel he had gone to the scene of the collision in February, 1969, on a day when the pavement was wet, and conducted several tests with an automobile to try to determine the proper coefficient of friction upon which to base his opinion as to the speed of the Buchanan vehicle. Appellees objected to his testimony concerning such tests on the ground that his investigation took place more than three years after the accident and it was not shown that the condition of the surface of the pavement was similar to its condition at the time of the collision, which objection was sustained. However, the witness was thereafter permitted to testify in elaborate detail as to his opinions, based upon the same coefficient of friction which had been used by the witness Pip-kin, which he was asked to assume, and he testified that in his opinion the Buchanan vehicle was traveling about 60 miles per hour when the brakes were applied, and about 25 miles per hour when it Struck the